oversight

File-Sharing Programs: Peer-to-Peer Networks Provide Ready Access to Child Pornography

Published by the Government Accountability Office on 2003-02-20.

Below is a raw (and likely hideous) rendition of the original report. (PDF)

                United States General Accounting Office

GAO             Report to the Chairman and Ranking
                Minority Member, Committee on
                Government Reform, House of
                Representatives

February 2003
                FILE-SHARING
                PROGRAMS
                Peer-to-Peer Networks
                Provide Ready Access
                to Child Pornography




                .




GAO-03-351
                                                February 2003


                                                FILE-SHARING PROGRAMS

                                                Peer-to-Peer Networks Provide Ready
Highlights of GAO-03-351, a report to the       Access to Child Pornography
Chairman and Ranking Minority Member,
Committee on Government Reform,
House of Representatives




The availability of child                       Child pornography is easily found and downloaded from peer-to-peer
pornography has dramatically                    networks. In one search using 12 keywords known to be associated with
increased in recent years as it has             child pornography on the Internet, GAO identified 1,286 titles and file names,
migrated from printed material to               determining that 543 (about 42 percent) were associated with child
the World Wide Web, becoming                    pornography images. Of the remaining, 34 percent were classified as adult
accessible through Web sites, chat
rooms, newsgroups, and now the
                                                pornography and 24 percent as nonpornographic. In another search using
increasingly popular peer-to-peer               three keywords, a Customs analyst downloaded 341 images, of which 149
file-sharing programs. These                    (about 44 percent) contained child pornography (see the figure below).
programs enable direct                          These results are in accord with increased reports of child pornography on
communication between users,                    peer-to-peer networks; since it began tracking these in 2001, the National
allowing users to access each                   Center for Missing and Exploited Children has seen a fourfold increase—
other’s files and share digital                 from 156 in 2001 to 757 in 2002. Although the numbers are as yet small by
music, images, and video.                       comparison to those for other sources (26,759 reports of child pornography
                                                on Web sites in 2002), the increase is significant.
GAO was requested to determine
the ease of access to child                     Juvenile users of peer-to-peer networks are at significant risk of inadvertent
pornography on peer-to-peer
networks; the risk of inadvertent
                                                exposure to pornography, including child pornography. Searches on
exposure of juvenile users of peer-             innocuous keywords likely to be used by juveniles (such as names of
to-peer networks to pornography,                cartoon characters or celebrities) produced a high proportion of
including child pornography; and                pornographic images: in our searches, the retrieved images included adult
the extent of federal law                       pornography (34 percent), cartoon pornography (14 percent), child erotica
enforcement resources available                 (7 percent), and child pornography (1 percent).
for combating child pornography
on peer-to-peer networks.                       While federal law enforcement agencies—including the FBI, Justice’s Child
                                                Exploitation and Obscenity Section, and Customs—are devoting resources
Because child pornography cannot                to combating child exploitation and child pornography in general, these
be accessed legally other than by               agencies do not track the resources dedicated to specific technologies used
law enforcement agencies, GAO
worked with the Customs Cyber-
                                                to access and download child pornography on the Internet. Therefore, GAO
Smuggling Center in performing                  was unable to quantify the resources devoted to investigating cases on peer-
searches: Customs downloaded                    to-peer networks. According to law enforcement officials, however, as tips
and analyzed image files, and GAO               concerning child pornography on peer-to-peer networks escalate, law
performed analyses based on                     enforcement resources are increasingly being focused on this area.
keywords and file names only.
                                                Classification of Images Downloaded through Peer-to-Peer File-Sharing Program
In commenting on a draft of this
report, the Department of Justice
agreed with the report’s findings
and provided additional
information.



www.gao.gov/cgi-bin/getrpt?GAO-03-351.

To view the full report, including the scope
and methodology, click on the link above.
For more information, contact Linda Koontz at
(202) 512-6240 or koontzl@gao.gov.
Contents


Letter                                                                                    1
               Results in Brief                                                           2
               Background                                                                 3
               Peer-to-Peer Applications Provide Easy Access to Child
                 Pornography                                                             11
               Juvenile Users of Peer-to-Peer Applications May Be Inadvertently
                 Exposed to Pornography                                                  14
               Federal Law Enforcement Agencies Are Beginning to Focus
                 Resources on Child Pornography on Peer-to-Peer Networks                 15
               Conclusions                                                               17
               Agency Comments and Our Evaluation                                        17

Appendix I     Objectives, Scope, and Methodology                                        19



Appendix II    Description of File Sharing and Peer-to-Peer
               Networks                                                                  21



Appendix III   Comments from the Department of Justice                                   26



Glossary                                                                                 29



Tables
               Table 1: Internet Technologies Providing Access to Child
                        Pornography                                                       7
               Table 2: Organizations and Agencies Involved with Peer-to-Peer
                        Child Pornography Efforts                                         9
               Table 3: NCMEC CyberTipline Referrals to Law Enforcement
                        Agencies, Fiscal Years 1998–2002                                 14


Figures
               Figure 1: Classification of 1,286 Titles and File Names of Images
                        Identified in KaZaA Search                                       12
               Figure 2: Classification of 341 Images Downloaded through KaZaA           13


               Page i                                      GAO-03-351 File-Sharing Programs
Figure 3: Classification of 177 Images of a Popular Singer, Child
         Actors, and a Cartoon Character Downloaded through
         KaZaA                                                                            15
Figure 4: Peer-to-Peer Models                                                             22
Figure 5: Topology of a Gnutella Network                                                  25




Abbreviations

CEOS              Child Exploitation and Obscenity Section
FBI               Federal Bureau of Investigation
IRC               Internet Relay Chat
MP3               Moving Pictures Experts Group (MPEG) MPEG-1 Audio
                  Layer-3
NCMEC             National Center for Missing and Exploited Children
NCVIP             National Child Victim Identification Program
NRC               National Research Council
P2P               peer to peer
URL               Uniform Resource Locator
VNS               virtual name space




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Page ii                                                GAO-03-351 File-Sharing Programs
United States General Accounting Office
Washington, DC 20548




                                   February 20, 2003

                                   The Honorable Tom Davis
                                   Chairman
                                   The Honorable Henry A. Waxman
                                   Ranking Minority Member
                                   Committee on Government Reform
                                   House of Representatives

                                   The availability of child pornography has dramatically increased in recent
                                   years as it has migrated from magazines, photographs, and videos to the
                                   World Wide Web. The Internet’s wide range of information search and
                                   retrieval technologies, which make it possible to quickly find a vast array
                                   of information, also make it easy to access, disseminate, and trade
                                   pornographic images and videos, including child pornography.
                                   Increasingly, child pornography is accessible through Web sites, chat
                                   rooms, newsgroups, and the increasingly popular peer-to-peer technology,
                                   which allows direct communication between computer users, so that they
                                   can access and share each other’s files (including images, video, and
                                   software).

                                   As requested, our objectives were to determine (1) the ease of access to
                                   child pornography on peer-to-peer networks; (2) the risk of inadvertent
                                   exposure of juvenile users of peer-to-peer networks to pornography,
                                   including child pornography; and (3) the extent of federal law enforcement
                                   resources available for combating child pornography on peer-to-peer
                                   networks.

                                   To address the first two objectives, we were assisted by the U.S. Customs
                                   CyberSmuggling Center in using a peer-to-peer application to search for
                                   image files matching keywords that were intended to identify pornography
                                   and child pornography images or that might accidentally identify
                                   pornographic images. The resulting files were downloaded, saved,
                                   analyzed, and classified by a U.S. Customs CyberSmuggling agent.1 To
                                   determine what federal law enforcement resources are allocated to
                                   combating child pornography on peer-to-peer networks, we analyzed



                                   1
                                    Because child pornography cannot be accessed legally other than by law enforcement
                                   agencies, we relied on Customs to download and analyze image files. We performed
                                   analyses based on titles and file names only.



                                   Page 1                                               GAO-03-351 File-Sharing Programs
                   resource allocation data at the Federal Bureau of Investigation and the
                   Child Exploitation and Obscenity Section within the Department of
                   Justice, and at the U.S. Customs Service and U.S. Secret Service within the
                   Department of the Treasury. We also received documentation about what
                   resources were being allocated to combat child pornography from the
                   National Center for Missing and Exploited Children, a federally funded
                   nonprofit organization that serves as a national resource center for
                   information related to crimes against children.

                   Appendix I contains a more detailed discussion of our objectives, scope,
                   and methodology. Appendix II provides more information on the
                   characteristics and use of peer-to-peer file-sharing programs.


                   Child pornography is easily accessed and downloaded from peer-to-peer
Results in Brief   networks. Using KaZaA, a popular peer-to-peer file-sharing program, we
                   used 12 keywords known to be associated with child pornography on the
                   Internet to search for child pornography image files. We identified 1,286
                   items, each with a title and file name, determining that 543 (about 42
                   percent) were associated with child pornography images. Of the
                   remaining, 34 percent were classified as adult pornography and 24 percent
                   as nonpornographic. In another search using three keywords, the Customs
                   CyberSmuggling Center also used KaZaA to search for and download child
                   pornography image files.2 This search identified 341 image files, of which
                   149 (about 44 percent) were classified as child pornography.3 The
                   remaining images were classified as child erotica4 (13 percent), adult
                   pornography (29 percent), or other (nonpornographic) images (14
                   percent). These results are consistent with observations of the National
                   Center for Missing and Exploited Children, which has stated that peer-to-
                   peer technology is increasingly popular for the dissemination of child
                   pornography. Although peer-to-peer networks are currently not the most
                   prominent source for child pornography, law enforcement agencies have
                   noted a significant increase in their use for this purpose. Since 2001, when
                   the center began to track peer-to-peer child pornography, peer-to-peer




                   2
                   Other popular peer-to-peer applications include Gnutella, BearShare, LimeWire, and
                   Morpheus.
                   3
                    Customs downloaded and analyzed image files for us because child pornography can be
                   legally accessed only by law enforcement agencies.
                   4
                   Erotic images of children that do not depict sexually explicit conduct.



                   Page 2                                                  GAO-03-351 File-Sharing Programs
             reports have increased more than fourfold—from 156 in 2001 to 757 in
             2002.

             When searching and downloading images on peer-to-peer networks,
             juvenile users face a significant risk of inadvertent exposure to
             pornography, including child pornography. Searches on innocuous
             keywords likely to be used by juveniles produce images of which a high
             proportion are pornographic: in our searches, the retrieved images
             included adult pornography (34 percent), cartoon pornography5 (14
             percent), child erotica (7 percent), and child pornography (1 percent).

             We were unable to determine the precise extent of federal law
             enforcement resources available for combating child pornography on
             peer-to-peer networks. While several law enforcement agencies—
             including the Federal Bureau of Investigation, Justice’s Child Exploitation
             and Obscenity Section, and Customs—devote resources to combating
             child exploitation and child pornography in general, they do not track the
             resources dedicated to specific technologies used to access and download
             child pornography on the Internet. Therefore, we were unable to quantify
             the resources devoted to investigations of peer-to-peer networking. Law
             enforcement officials told us, however, that as they receive larger numbers
             of tips concerning child pornography on peer-to-peer networks, they are
             focusing more law enforcement resources in this area.

             In commenting on a draft of this report, the Department of Justice agreed
             with the report’s findings and provided some additional information;
             Justice’s comments are reprinted in appendix III. We also received
             technical comments from the U.S. Secret Service and the U.S. Customs
             Service. Their comments have been incorporated in the report as
             appropriate.


             Federal statutes provide for civil and criminal penalties for the production,
Background   advertising, possession, receipt, distribution, and sale of child
             pornography.6 Of particular relevance to this report, the child pornography
             statutes prohibit the use of any means of interstate or foreign commerce
             (which will typically include the use of an interactive computer service) to
             sell, advertise, distribute, receive, or possess child pornography.


             5
             Images of cartoon characters depicting sexually explicit conduct.
             6
             See chapter 110 of Title 18, U.S. Code.




             Page 3                                                 GAO-03-351 File-Sharing Programs
Additionally, federal obscenity statutes prohibit the use of any means of
interstate or foreign commerce or an interactive computer service to
import, transport, or distribute obscene material or to transfer obscene
material to persons under the age of 16.7

Child pornography is defined by statute as the visual depiction of a
minor—a person under 18 years of age—engaged in sexually explicit
conduct.8 By contrast, for material to be defined as obscene depends on
whether an average person, applying contemporary community standards,
would interpret the work—including images—to appeal to the prurient
interest and to be patently offensive, and whether a reasonable person
would find the material lacks serious literary, artistic, political, or
scientific value.9

In addition to making it a crime to transport, receive, sell, distribute,
advertise, or possess child pornography in interstate or foreign commerce,
federal child pornography statutes prohibit, among other things, the use of
a minor in producing pornography, and they provide for criminal and civil
forfeiture of real and personal property used in making child pornography
and of the profits of child pornography.10 Child pornography, which is
intrinsically related to the sexual abuse of children, is unprotected by the
First Amendment.11 Nor does the First Amendment protect the production,
distribution, or transfer of obscene material.12



7
See chapter 71 of Title 18, U.S. Code.
8
See 18 U.S.C. § 2256(8).
9
 See Miller v. California, 413 U.S. 15 (1973). In Miller, the Supreme Court created a three-
part test to determine whether a work is obscene. The Miller test, as interpreted by
subsequent Supreme Court jurisprudence, asks (a) whether an average person applying
contemporary community standards would find that the material, taken as a whole, appeals
to the prurient interest; (b) whether an average person applying contemporary community
standards would find that the material depicts proscribed behavior in a patently offensive
manner; and (c) whether a reasonable person would find that the material, taken as a
whole, lacks serious literary, artistic, political, or scientific value. As the Miller test is
unrelated to child pornography, it does not account for the government’s compelling
interest in protecting children from sexual exploitation.
10
    See chapter 110, Title 18, U.S. Code.
11
    See New York v. Ferber, 458 U.S. 747 (1982).
12
 See Roth v. United States, 354 U.S. 476 (1957). In contrast, the private possession of
obscenity in one’s home is protected by the First Amendment. See Stanley v. Georgia,
394 U.S. 557 (1969).




Page 4                                                   GAO-03-351 File-Sharing Programs
In enacting the Child Pornography Prevention Act of 1996,13 Congress
sought to expand the federal prohibition against child pornography from
images that involve actual children to sexually explicit images that only
appear to depict minors but were produced without using any real
children. The act defines child pornography as “any visual depiction,
including any photograph, film, video, picture, or computer or computer-
generated image or picture” that “is, or appears to be, of a minor engaging
in sexually explicit conduct” or is “advertised, promoted, presented,
described, or distributed in such a manner that conveys the impression
that the material is or contains a visual depiction of a minor engaging in
sexually explicit conduct.” Last year, the Supreme Court struck down this
legislative attempt to ban “virtual” child pornography14 in Ashcroft v. The
Free Speech Coalition, ruling that the expansion of the act to material that
did not involve and thus harm actual children in its creation is an
unconstitutional violation of free speech rights. According to government
officials, this ruling may increase the difficulty faced by law enforcement
agencies in prosecuting those who produce and possess child
pornography. Since the government must establish that the digital images
of children engaged in sexual acts are those of real children, it may be
difficult to prosecute cases in which the defendants claim that the images
in question are of “virtual” children.




13
 Section 121, P.L. 104-208, 110 Stat. 3009-26.
14
 According to the Justice Department, rapidly advancing technology has raised the
possibility of creating images of child pornography without the use of a real child (“virtual”
child pornography). Totally virtual creations would be both time intensive and, for now,
prohibitively costly to produce. However, the technology has led to a ready defense (the
“virtual” porn defense) against prosecution under laws that are limited to sexually explicit
depictions of actual minors. Because the technology does exist today to alter images in a
manner that disguises the identity of the real child or makes the image seem computer-
generated, it encourages producers and distributors of child pornography to alter
depictions of actual children in slight ways to make them not only unidentifiable, but also
appear as if they were virtual creations—and thereby attempt to defeat prosecution. In
contrast to the weighty task of creating an entire image out of whole cloth, it is not difficult
or expensive to use readily available technology to disguise depictions of real children to
make them unidentifiable or to make them appear computer generated.




Page 5                                                    GAO-03-351 File-Sharing Programs
The Internet Has Emerged    Historically, pornography, including child pornography, tended to be
as the Principal Tool for   found mainly in photographs, magazines, and videos.15 The arrival and the
Exchanging Child            rapid expansion of the Internet and its technologies, the increased
                            availability of broadband Internet services, advances in digital imaging
Pornography                 technologies, and the availability of powerful digital graphic programs
                            have brought about major changes in both the volume and the nature of
                            available child pornography. The proliferation of child pornography on the
                            Internet is prompting wide concern. According to a recent survey, over 90
                            percent of Americans say they are concerned about child pornography on
                            the Internet, and 50 percent of Americans cite child pornography as the
                            single most heinous crime that takes place on line.16

                            According to experts, pornographers have traditionally exploited—and
                            sometimes pioneered—emerging communication technologies—from the
                            dial-in bulletin board systems of the 1970s to the World Wide Web—to
                            access, trade, and distribute pornography, including child pornography.17
                            Today, child pornography is available through virtually every Internet
                            technology (see table 1).




                            15
                             John Carr, Theme Paper on Child Pornography for the 2nd World Congress on
                            Commercial Sexual Exploitation of Children, NCH Children’s Charities, Children &
                            Technology Unit (Yokohama, 2001).
                            (http://www.ecpat.net/eng/Ecpat_inter/projects/monitoring/wc2/yokohama_theme_child_p
                            ornography.pdf)
                            16
                              Susannah Fox and Oliver Lewis, Fear of Online Crime: Americans Support FBI
                            Interception of Criminal Suspects’ Email and New Laws to Protect Online Privacy, Pew
                            Internet & American Life Project (Apr. 2, 2001).
                            (http://www.pewInternet.org/reports/pdfs/PIP_Fear_of_crime.pdf)
                            17
                              Frederick E. Allen, “When Sex Drives Technological Innovation and Why It Has to,”
                            American Heritage Magazine, vol. 51, no. 5 (September 2000), p. 19.
                            (http://www.plannedparenthood.org/education/updatearch.html)
                            Allen notes that pornographers have driven the development of some of the Internet
                            technologies, including the development of systems used to verify on-line financial
                            transactions and that of digital watermarking technology to prevent the unauthorized use
                            of on-line images.




                            Page 6                                                 GAO-03-351 File-Sharing Programs
Table 1: Internet Technologies Providing Access to Child Pornography

 Technology                  Characteristics
 World Wide Web              Web sites provide on-line access to text and multimedia
                             materials identified and accessed through the uniform
                             resource locator (URL).
 Usenet                      A distributed electronic bulletin system, Usenet offers over
                             80,000 newsgroups, with many newsgroups dedicated to
                             sharing of digital images.
 Peer-to-peer file-sharing   Internet applications operating over peer-to-peer networks
 programs                    enable direct communication between users. Used largely
                             for sharing of digital music, images, and video, peer-to-peer
                             applications include BearShare, Gnutella, LimeWire, and
                             KaZaA. KaZaA is the most popular, with over 3 million
                             KaZaA users sharing files at any time.
 E-mail                      E-mail allows the transmission of messages over a network
                             or the Internet. Users can send E-mail to a single recipient or
                             broadcast it to multiple users. E-mail supports the delivery of
                             attached files, including image files.
 Instant messaging           Instant messaging is not a dial-up system like the telephone;
                             it requires that both parties be on line at the same time.
                             AOL’s Instant Messenger and Microsoft’s MSN Messenger
                             and Internet Relay Chat are the major instant messaging
                             services. Users may exchange files, including image files.
 Chat and Internet Relay     Chat technologies allow computer conferencing using the
 Chat                        keyboard over the Internet between two or more people.
Source: GAO.



Among the principal channels for the distribution of child pornography are
commercial Web sites, Usenet newsgroups, and peer-to-peer networks.18

Web sites. According to recent estimates, there are about 400,000
commercial pornography Web sites worldwide,19 with some of the sites
selling pornographic images of children. The profitability and the
worldwide reach of the child pornography trade was recently
demonstrated by an international child pornography ring that included a
Texas-based firm providing credit card billing and password access
services for one Russian and two Indonesian child pornography Web sites.


18
 According to Department of Justice officials, other forums and technologies are used to
disseminate pornography on the Internet. These include Web portal communities such as
Yahoo! Groups and MSN Groups, as well as file servers operating on Internet Relay Chat
channels.
19
 Dick Thornburgh and Herbert S. Lin, editors, Youth, Pornography, and The Internet,
National Academy Press (Washington, D.C.: 2002).
(http://www.nap.edu/html/youth_internet/)




Page 7                                                  GAO-03-351 File-Sharing Programs
According to the U.S. Postal Inspection Service, the ring grossed as much
as $1.4 million in just 1 month selling child pornography to paying
customers.

Usenet. Usenet newsgroups are also providing access to pornography,
with several of the image-oriented newsgroups being focused on child
erotica and child pornography. These newsgroups are frequently used by
commercial pornographers who post “free” images to advertise adult and
child pornography available for a fee from their Web sites. The increase in
the availability of child pornography in Usenet newsgroups represents a
change from the mid-1990’s, when a 1995–96 study of 9,800 randomly
selected images taken from 32 Usenet newsgroups found that only a small
fraction of posted images contained child pornography themes.20

Peer-to-peer networks. Although peer-to-peer file-sharing programs are
largely known for the extensive sharing of copyrighted digital music,21 they
are emerging as a conduit for the sharing of child pornography images and
videos. A recent study by congressional staff found that one use of file-
sharing programs is to exchange pornographic materials, such as adult
videos.22 The study found that a single search for the term “porn” using a
similar file-sharing program yielded over 25,000 files, more than 10,000 of
which were video files appearing to contain pornographic images. In
another study, focused on the availability of pornographic video files on
peer-to-peer sharing networks, a sample of 507 pornographic video files
retrieved with a file-sharing program included about 3.7 percent child
pornography videos.23




20
 Michael D. Mehta, “Pornography in Usenet: A Study of 9,800 Randomly Selected Images,”
CyberPsychology and Behavior, vol. 4, no. 6 (2001).
21
  According to the Yankee Group, a technology research and consulting firm, Internet users
aged 14 and older downloaded 5.16 billion audio files in the United States via unlicensed
file-sharing services in 2001.
22
 Minority Staff, Children’s Access to Pornography through Internet File-Sharing
Programs, Special Investigations Division, Committee on Government Reform, U.S. House
of Representatives (July 27, 2001).
(http://www.house.gov/reform/min/pdfs/pdf_inves/pdf_pornog_rep.pdf)
23
 Michael D. Mehta, Don Best, and Nancy Poon, “Peer-to-Peer Sharing on the Internet: An
Analysis of How Gnutella Networks Are Used to Distribute Pornographic Material,”
Canadian Journal of Law and Technology, vol. 1, no. 1 (January 2002).
(http://cjlt.dal.ca/vol1_no1/articles/01_01_MeBePo_gnutella.pdf)




Page 8                                                 GAO-03-351 File-Sharing Programs
Several Agencies Have        Table 2 shows the key national organizations and agencies that are
Law Enforcement              currently involved in efforts to combat child pornography on peer-to-peer
Responsibilities Regarding   networks.
Child Pornography on
Peer-to-Peer Networks        Table 2: Organizations and Agencies Involved with Peer-to-Peer Child Pornography
                             Efforts

                                 Agency                Unit                 Focus
                                 Nonprofit
                                 National Center for   Exploited Child      Works with the Customs Service, Postal
                                 Missing and           Unit                 Service, and the FBI to analyze and
                                 Exploited Children                         investigate child pornography leads.
                                 Federal entities
                                 Department of         Federal Bureau of    Proactively investigates crimes against
                                                                    a
                                 Justice               Investigation        children. Operates a national “innocent
                                                                            Images Initiative” to combat Internet-related
                                                                            sexual exploitation of children.
                                                       Criminal Division,   Is a specialized group of attorneys who,
                                                       Child Exploitation   among other things, prosecute those who
                                                       and Obscenity        possess, manufacture, or distribute child
                                                       Section              pornography. Its High Tech Investigative Unit
                                                                            actively conducts on-line investigations to
                                                                            identify distributors of obscenity and child
                                                                            pornography.
                                 Department of the     U.S. Customs         Conducts international child pornography
                                 Treasury              Service              investigations as part of its mission to
                                                       CyberSmuggling       investigate international criminal activity
                                                       Centera              conducted on or facilitated by the Internet.
                                                       U.S. Secret          Provides forensic and technical assistance in
                                                               a
                                                       Service              matters involving missing and sexually
                                                                            exploited children.
                             Source: GAO.
                             a
                             Agency has staff assigned to NCMEC.


                             The National Center for Missing and Exploited Children (NCMEC), a
                             federally funded nonprofit organization, serves as a national resource
                             center for information related to crimes against children. Its mission is to
                             find missing children and prevent child victimization. The center’s
                             Exploited Child Unit operates the CyberTipline, which receives child
                             pornography tips provided by the public; its CyberTipline II also receives
                             tips from Internet service providers. The Exploited Child Unit investigates
                             and processes tips to determine if the images in question constitute a
                             violation of child pornography laws. The CyberTipline provides
                             investigative leads to the Federal Bureau of Investigation (FBI), U.S.
                             Customs, the Postal Inspection Service, and state and local law
                             enforcement agencies. The FBI and the U.S. Customs also investigate
                             leads from Internet service providers via the Exploited Child Unit’s


                             Page 9                                                    GAO-03-351 File-Sharing Programs
    CyberTipline II. The FBI, Customs Service, Postal Inspection Service, and
    Secret Service have staff24 assigned directly to NCMEC as analysts.

    Two organizations in the Department of Justice have responsibilities
    regarding child pornography: the FBI and the Justice Criminal Division’s
    Child Exploitation and Obscenity Section (CEOS).25

•   The FBI investigates various crimes against children, including federal
    child pornography crimes involving interstate or foreign commerce. It
    deals with violations of child pornography laws related to the production
    of child pornography; selling or buying children for use in child
    pornography; and the transportation, shipment, or distribution of child
    pornography by any means, including by computer.
•   CEOS prosecutes child sex offenses and trafficking in women and children
    for sexual exploitation. Its mission includes prosecution of individuals
    who possess, manufacture, produce, or distribute child pornography; use
    the Internet to lure children to engage in prohibited sexual conduct; or
    traffic in women and children interstate or internationally to engage in
    sexually explicit conduct.

    Two organizations in the Department of the Treasury have responsibilities
    regarding child pornography: the Customs Service26 and the Secret Service.

•   The Customs Service targets illegal importation and trafficking in child
    pornography and is the country’s front line of defense in combating child
    pornography distributed through various channels, including the Internet.
    Customs is involved in cases with international links, focusing on
    pornography that enters the United States from foreign countries. The
    Customs CyberSmuggling Center has the lead in the investigation of
    international and domestic criminal activities conducted on or facilitated
    by the Internet, including the sharing and distribution of child
    pornography on peer-to-peer networks. Customs maintains a reporting


    24
      In commenting on our report, the Secret Service noted that its staff assigned to NCMEC
    include analysts and an agent.
    25
     Two additional Justice agencies are involved in combating child pornography: the U.S.
    Attorneys Offices and the Office of Juvenile Justice and Delinquency Prevention. The 94
    U.S. Attorneys Offices can prosecute federal child exploitation-related cases; the Office of
    Juvenile Justice and Delinquency Prevention funds the Internet Crimes Against Children
    Task Force Program, which encourages multijurisdictional and multiagency responses to
    crimes against children involving the Internet.
    26
     Under the Homeland Security Act of 2002, the Customs Service is to become part of the
    new Department of Homeland Security.




    Page 10                                                  GAO-03-351 File-Sharing Programs
                           link with NCMEC, and it acts on tips received via the CyberTipline from
                           callers reporting instances of child pornography on Web sites, Usenet
                           newsgroups, chat rooms, or the computers of users of peer-to-peer
                           networks. The center also investigates leads from Internet service
                           providers via the Exploited Child Unit’s CyberTipline II.
                       •   The U.S. Secret Service does not investigate child pornography cases on
                           peer-to-peer networks; however, it does provide forensic and technical
                           support to NCMEC, as well as to state and local agencies involved in cases
                           of missing and exploited children.

                           In November 2002, we reported that federal agencies are effectively
                           coordinating their efforts to combat child pornography, and we
                           recommended that the Attorney General designate the Postal Inspection
                           Service and Secret Service as agencies that should receive reports and tips
                           of child pornography under the Protection of Children from Sexual
                           Predators Act of 1998 in addition to the FBI and Customs.27

                           The Department of Justice, while agreeing with our finding that federal
                           agencies have mechanisms in place to coordinate their efforts, did not
                           fully support our conclusion and recommendation that federal
                           coordination efforts would be further enhanced if the Postal Inspection
                           Service and the Secret Service were provided direct access to tips
                           reported to NCMEC by remote computing service and electronic
                           communication service providers. Justice said that the FBI and Customs,
                           the agencies that currently have direct access, can and do share these tips
                           with the Secret Service and the Postal Inspection Service, as appropriate,
                           and Justice believes that this coordination has been effective. Justice
                           questioned whether coordination would be further enhanced by having the
                           Secret Service and the Postal Inspection Service designated to receive
                           access to these tips directly from NCMEC; however, Justice said that it is
                           studying this issue as it finalizes regulations implementing the statute.

                           Child pornography is easily shared and accessed through peer-to-peer file-
Peer-to-Peer               sharing programs. Our analysis of 1,286 titles and file names identified
Applications Provide       through KaZaA searches on 12 keywords28 showed that 543 (about 42
                           percent) of the images had titles and file names associated with child
Easy Access to Child
Pornography
                           27
                             U.S. General Accounting Office, Combating Child Pornography: Federal Agencies
                           Coordinate Law Enforcement Efforts, but an Opportunity Exists for Further
                           Enhancements, GAO-03-272 (Washington, D.C.: Nov. 29, 2002).
                           28
                            The 12 keywords were provided by the Cybersmuggling Center as examples known to be
                           associated with child pornography on the Internet.




                           Page 11                                             GAO-03-351 File-Sharing Programs
pornography images.29 Of the remaining files, 34 percent were classified as
adult pornography, and 24 percent as nonpornographic (see fig. 1). No
files were downloaded for this analysis.

Figure 1: Classification of 1,286 Titles and File Names of Images Identified in KaZaA
Search




The ease of access to child pornography files was further documented by
retrieval and analysis of image files, performed on our behalf by the
Customs CyberSmuggling Center. Using 3 of the 12 keywords that we used
to document the availability of child pornography files, a CyberSmuggling
Center analyst used KaZaA to search, identify, and download 305 files,
including files containing multiple images and duplicates. The analyst was
able to download 341 images from the 305 files identified through the
KaZaA search.

The CyberSmuggling Center analysis of the 341 downloaded images
showed that 149 (about 44 percent) of the downloaded images contained
child pornography (see fig. 2). The center classified the remaining images
as child erotica (13 percent), adult pornography (29 percent), or
nonpornographic (14 percent).


29
 We categorized a file as child pornography if one keyword indicating a minor and one
word with a sexual connotation occurred in either the title or file name. Files with sexual
connotation in title or name but without age indicators were classified as adult
pornography.




Page 12                                                  GAO-03-351 File-Sharing Programs
Figure 2: Classification of 341 Images Downloaded through KaZaA




Note: GAO analysis of data provided by the Customs CyberSmuggling Center.


These results are consistent with the observations of NCMEC, which has
stated that peer-to-peer technology is increasingly popular for the
dissemination of child pornography. However, it is not the most prominent
source for child pornography. As shown in table 3, since 1998, most of the
child pornography referred by the public to the CyberTipline was found on
Internet Web sites. Since 1998, the center has received over 76,000 reports
of child pornography, of which 77 percent concerned Web sites, and only
1 percent concerned peer-to-peer networks. Web site referrals have grown
from about 1,400 in 1998 to over 26,000 in 2002—or about a nineteenfold
increase. NCMEC did not track peer-to-peer referrals until 2001. In 2002,
peer-to-peer referrals increased more than fourfold, from 156 to 757,
reflecting the increased popularity of file-sharing programs.




Page 13                                                  GAO-03-351 File-Sharing Programs
                      Table 3: NCMEC CyberTipline Referrals to Law Enforcement Agencies, Fiscal Years
                      1998–2002

                                                                                                     Number of tips
                       Technology                                               1998             1999      2000       2001           2002
                       Web sites                                                1,393            3,830   10,629     18,052         26,759
                       E-mail                                                     117              165      120      1,128          6,245
                       Peer-to-peer                                                —                —        —         156            757
                       Usenet newsgroups & bulletin
                       boards                                                     531              987           731        990       993
                       Unknown                                                     90              258           260        430       612
                       Chat rooms                                                 155              256           176        125       234
                       Instant Messaging                                           27               47            50         80        53
                       File Transfer Protocol                                      25               26            58         64        23
                       Total                                                    2,338            5,569        12,024     21,025    35,676
                      Source: Exploited Child Unit, National Center for Missing and Exploited Children.




                      Juvenile users of peer-to-peer networks face a significant risk of
Juvenile Users of     inadvertent exposure to pornography when searching and downloading
Peer-to-Peer          images. In a search using innocuous keywords likely to be used by
                      juveniles searching peer-to-peer networks (such as names of popular
Applications May Be   singers, actors, and cartoon characters), almost half of the images
Inadvertently         downloaded were classified as adult or cartoon pornography. Juvenile
                      users may also be inadvertently exposed to child pornography through
Exposed to            such searches, but the risk of such exposure is smaller than that of
Pornography           exposure to pornography in general.

                      To document the risk of inadvertent exposure of juvenile users to
                      pornography, the Customs CyberSmuggling Center performed KaZaA
                      searches using innocuous keywords that would likely be used by juveniles.
                      The center image searches used three keywords representing the names of
                      a popular female singer, child actors, and a cartoon character. A center
                      analyst performed the search, retrieval, and analysis of the images, each of
                      which was classified into one of five categories: child pornography, child
                      erotica, adult pornography, cartoon pornography, or nonpornographic.
                      The searches produced 157 files, some of which were duplicates. The
                      analyst was able to download 177 images from the 157 files identified
                      through the search.

                      As shown in figure 3, our analysis of the CyberSmuggling Center’s
                      classification of the 177 downloaded images determined that 61 images
                      contained adult pornography (34 percent), 24 images consisted of cartoon



                      Page 14                                                                             GAO-03-351 File-Sharing Programs
                       pornography (14 percent), 13 images contained child erotica (7 percent),
                       and 2 images (1 percent) contained child pornography. The remaining 77
                       images were classified as nonpornographic.

                       Figure 3: Classification of 177 Images of a Popular Singer, Child Actors, and a
                       Cartoon Character Downloaded through KaZaA




                       Note: GAO analysis of data provided by the Customs CyberSmuggling Center.



                       Because law enforcement agencies do not track the resources dedicated to
Federal Law            specific technologies used to access and download child pornography on
Enforcement            the Internet, we were unable to quantify the resources devoted to
                       investigations concerning peer-to-peer networks. These agencies
Agencies Are           (including the FBI, CEOS, and Customs) do devote significant resources to
Beginning to Focus     combating child exploitation and child pornography in general. Law
                       enforcement officials told us, however, that as tips concerning child
Resources on Child     pornography on the peer-to-peer networks increase, they are beginning to
Pornography on Peer-   focus more law enforcement resources on this issue.
to-Peer Networks       In fiscal year 2002, the key organizations involved in combating child
                       pornography on peer-to-peer networks reported the following levels of
                       funding:




                       Page 15                                                  GAO-03-351 File-Sharing Programs
•   NCMEC received about $12 million for its congressionally mandated role
    as the national resource center and clearinghouse. NCMEC also received
    about $10 million for law enforcement training and about $3.3 million for
    the Exploited Child Unit and the promotion of its CyberTipline. From the
    appropriated amounts, NCMEC allocated $916,000 to combat child
    pornography and referred 913 tips concerning peer-to-peer networks to
    law enforcement agencies.
•   The FBI allocated $38.2 million and 228 agents and support personnel to
    combat child pornography through its Innocent Images unit. Since fiscal
    year 1996, the Innocent Image National Initiative opened 7,067 cases,
    obtained 1,811 indictments, performed 1,886 arrests, and secured 1,850
    convictions or pretrial diversions in child pornography cases. According to
    FBI officials, they are aware of the use of peer-to-peer networks to
    disseminate child pornography and have efforts under way to work with
    some of the peer-to-peer companies to solicit their cooperation in dealing
    with this issue.
•   CEOS allocated $4.38 million and 28 personnel to combat child
    exploitation and obscenity offenses. It has recently launched an effort, the
    High Tech Investigative Unit, dealing with investigating any Internet
    medium that distributes child pornography, including peer-to-peer
    networks.
•   Customs allocated $15.6 million and over 144,000 hours to combating child
    exploitation and obscenity offenses.30 The CyberSmuggling Center is
    beginning to actively monitor the file sharing of child pornography on
    peer-to-peer networks and is devoting one half-time investigator to this
    effort. As of December 16, 2002, the center has sent 21 peer-to-peer
    investigative leads to the field offices for follow-up action. Four of these
    leads have search warrants pending, two have been referred to local law
    enforcement, and five have been referred to foreign law enforcement
    agencies.

    In addition, to facilitate the identification of the victims of child
    pornographers, the CyberSmuggling Center is devoting resources to the
    National Child Victim Identification Program, a consolidated information
    system containing seized images that is designed to allow law enforcement
    officials to quickly identify and combat the current abuse of children
    associated with the production of child pornography. The system’s
    database is being populated with all known and unique child pornographic
    images obtained from national and international law enforcement sources



    30
     Customs is unable to separate the staff hours devoted or funds obligated to combating
    child pornography from those dedicated to combating child exploitation in general.




    Page 16                                               GAO-03-351 File-Sharing Programs
                     and from CyberTipline reports filed with NCMEC. It will initially hold over
                     100,000 images that have been collected by federal law enforcement
                     agencies from various sources, including old child pornography
                     magazines.31 According to Customs officials, this information will help,
                     among other things, to determine whether actual children were used to
                     produce child pornography images by matching them with images of
                     children from magazines published before modern imaging technology
                     was invented. Such evidence can be used to counter the assertion that
                     only virtual children appear in certain images.

                     The system is housed at the Customs CyberSmuggling Center and is to be
                     accessed remotely in “read only” format by the FBI, CEOS, the U.S. Postal
                     Inspection Service, and NCMEC. An initial version of the system was
                     deployed at the Customs CyberSmuggling Center in September 2002; the
                     system became operational in January 2003.32


                     It is easy to access and download child pornography on peer-to-peer
Conclusions          networks. Juvenile users of peer-to-peer networks also face a significant
                     risk of inadvertent exposure to pornography, including child pornography.
                     We were unable to determine the extent of federal law enforcement
                     resources available for combating child pornography on peer-to-peer
                     networks; the key law enforcement agencies devote resources to
                     combating child exploitation and child pornography in general, but they do
                     not track the resources dedicated to peer-to-peer technologies in
                     particular.


                     The Assistant Attorney General, Criminal Division, Department of Justice,
Agency Comments      provided written comments on a draft of this report, which are reprinted
and Our Evaluation   in appendix III. The Department of Justice agreed with the report’s
                     findings, provided additional information on the mission and capabilities
                     of the High Tech Investigative Unit (part of its Criminal Division’s Child
                     Exploitation and Obscenity Section), and offered comments on the
                     description and purpose of Customs’ National Child Victim Identification



                     31
                      According to federal law enforcement agencies, most of the child pornography published
                     before 1970 has been digitized and made widely available on the Internet.
                     32
                       One million dollars has already been spent on the system, with an additional $5 million
                     needed for additional hardware, the expansion of the image database, and access for all
                     involved agencies. The 10-year lifecycle cost of the system is estimated to be $23 million.




                     Page 17                                                  GAO-03-351 File-Sharing Programs
Program. In response, we have revised our report to add these
clarifications. We also received written technical comments from the
Department of Justice, which we have incorporated as appropriate.

We received written technical comments from the Assistant Director,
Office of Inspection, U.S. Secret Service, and from the Acting Director,
Office of Planning, U.S. Customs Service. Their comments have been
incorporated in the report as appropriate.


As agreed with your office, unless you publicly announce the contents of
this report earlier, we plan no further distribution until 30 days from the
report date. At that time, we will send copies of this report to the
Chairmen and Ranking Minority Members of other Senate and House
committees and subcommittees that have jurisdiction and oversight
responsibility for the Departments of Justice and the Treasury. We will
also send copies to the Attorney General and to the Secretary of the
Treasury. Copies will be made available to others on request. In addition,
this report will be available at no charge on the GAO Web site at
http://www.gao.gov.

If you have any questions concerning this report, please call me at (202)
512-6240 or Mirko J. Dolak, Assistant Director, at (202) 512-6362. We can
be also reached by E-mail at koontzl@gao.gov and dolakm@gao.gov,
respectively. Key contributors to this report were Barbara S. Collier,
James M. Lager, Neelaxi V. Lakhmani, James R. Sweetman, Jr., and Jessie
Thomas.




Linda D. Koontz
Director, Information Management Issues




Page 18                                        GAO-03-351 File-Sharing Programs
                 Appendix I:
Appendix I: Objectives,
            Appendix I: Scope,
                        Objectives,
                               and Scope,
Methodology

                 Our objectives were to

             •   determine the ease of access to child pornography on peer-to-peer
                 networks,
             •   assess the risk of inadvertent exposure of juvenile users of peer-to-peer
                 networks to pornography, including child pornography, and
             •   determine the extent of federal law enforcement resources available for
                 combating child pornography on peer-to-peer networks.

                 To determine the availability of child pornography on peer-to-peer
                 networks, we used a popular peer-to-peer application—KaZaA—to search
                 for and identify image files that appear to be child pornography. Our
                 analysts used keywords provided by the Customs CyberSmuggling Center.
                 These keywords were intended to identify pornographic images; examples
                 of the keywords include preteen, underage, and incest.

                 Once the names and titles of image files were gathered, we classified and
                 analyzed them based on file names and keywords. Each file was classified
                 as child pornography, adult pornography, or nonpornographic. For a file to
                 be considered possible child pornography, the title, file name, or both had
                 to include at least one word with a sexual connotation and an age-related
                 keyword indicating that the subject is a minor. Files depicting adult
                 pornography included any file that had words of a sexual nature in the title
                 or file name. No files were downloaded for this analysis.

                 To determine the ease of access, we used three keywords from the initial
                 list to perform another search. The resulting files were downloaded, saved,
                 and analyzed by a Customs agent. Because child pornography cannot be
                 accessed legally other than by law enforcement agencies, we relied on
                 Customs to download and analyze files. Our own analyses were based on
                 keywords and file names only. The Customs agent classified each of the
                 downloaded files into one of four categories: child pornography, child
                 erotica, adult pornography, or nonpornographic. The user with the largest
                 number of shared files that appeared to be child pornography was also
                 identified, and the shared folder was captured. The titles and names of
                 files in the user’s shared directory were then analyzed and classified by a
                 GAO analyst using the same classification criteria used in original analysis.

                 To assess the risk of inadvertent exposure of juvenile users of peer-to-peer
                 networks to pornography, a CyberSmuggling Center analyst conducted
                 another search using three keywords that are names of popular celebrities
                 and a cartoon character. The Customs analyst performed the search,
                 retrieval, and analysis of the images. Each of the images downloaded was



                 Page 19                                        GAO-03-351 File-Sharing Programs
Appendix I: Objectives, Scope, and
Methodology




classified into one of five categories: adult pornography, child
pornography, child erotica, cartoon pornography, or nonpornographic.

To determine what federal law enforcement resources were allocated to
combating child pornography on peer-to-peer networks, we obtained
resource allocation data and interviewed officials at the U.S. Customs
Service, the Department of Justice’s Child Exploitation and Obscenity
Section, and the Federal Bureau of Investigation. We also received
information about what resources were being allocated to combat child
pornography from the U.S. Secret Service and the National Center for
Missing and Exploited Children.

We performed our work between July and October 2002 at the U.S. Secret
Service in Baltimore, Maryland, and the U.S. Customs Service, Customs
CyberSmuggling Center, in Fairfax, Virginia, under the Department of the
Treasury; and at the Child Exploitation and Obscenity Section and the
Federal Bureau of Investigation, under the Department of Justice, in
Washington, D.C. We also worked with the National Center for Missing
and Exploited Children in Alexandria, Virginia. Our work was conducted
in accordance with generally accepted government auditing standards.




Page 20                                     GAO-03-351 File-Sharing Programs
               Appendix II: Description of File Sharing and
Appendix II: Description of File Sharing and
               Peer-to-Peer Networks



Peer-to-Peer Networks

               Peer-to-peer file-sharing programs represent a major change in the way
               Internet users find and exchange information. Under the traditional
               Internet client/server model, the access to information and services is
               accomplished by the interaction between users (clients) and servers—
               usually Web sites or portals. A client is defined as a requester of services,
               and a server is defined as the provider of services. Unlike the traditional
               model, the peer-to-peer model enables consenting users—or peers—to
               directly interact and share information with each other without the
               intervention of a server. A common characteristic of peer-to-peer
               programs is that they build virtual networks with their own mechanisms
               for routing message traffic.1

               The ability of peer-to-peer networks to provide services and connect users
               directly has resulted in a large number2 of powerful applications built
               around this model.3 These range from the SETI@home network (where
               users share the computing power of their computers to search for
               extraterrestrial life) to the popular KaZaA file-sharing program (used to
               share music and other files).

               As shown in figure 4,4 there are two main models of peer-to-peer networks:
               (1) the centralized model, based on a central server or broker that directs
               traffic between individual registered users, and (2) the decentralized




               1
                Matei Ripenau, Ian Foster, and Adriana Iamnitchi, “Mapping the Gnutella Network:
               Properties of Large Scale Peer-to-Peer Systems and Implication for System Design,” IEEE
               Internet Computing, vol. 6, no. 1 (January–February 2002).
               (people.cs.uchicago.edu/~matei/PAPERS/ic.pdf)
               2
                Zeropaid.com, a file-sharing portal, lists 88 different peer-to-peer file-sharing programs
               available for download. (http://www.zeropaid.com/php/filesharing.php)
               3
                Geoffrey Fox and Shrideep Pallickara, “Peer-to-Peer Interactions in Web Brokering
               Systems,” Ubiquity, vol. 3, no. 15 (May 28–June 3, 2002) (published by Association of
               Computer Machinery). (http://www.acm.org/ubiquity/views/g_fox_2.html)
               4
                Illustration adapted by Lt. Col. Mark Bontrager from original by Bob Knighten, “Peer-to-
               Peer Computing,” briefing to Peer-to-Peer Working Groups (August 24, 2000), in Mark D.
               Bontrager, Peering into the Future: Peer-to-Peer Technology as a Model for Distributed
               Joint Battlespace Intelligence Dissemination and Operational Tasking, Thesis, School of
               Advanced Airpower Studies, Air University, Maxwell Air Force Base, Alabama (June 2001).




               Page 21                                                   GAO-03-351 File-Sharing Programs
                                Appendix II: Description of File Sharing and
                                Peer-to-Peer Networks




                                model, based on the Gnutella5 network, in which individuals find and
                                interact directly with each other.

Figure 4: Peer-to-Peer Models




                                Note: Adapted from Mark Bontrager’s adaptation of original by Bob Knighten.


                                As shown in figure 4, the centralized model relies on a central
                                server/broker to maintain directories of shared files stored on the
                                respective computers of the registered users of the peer-to-peer network.
                                When Bob submits a request for a particular file, the server/broker creates
                                a list of files matching the search request by checking the request with its
                                database of files belonging to registered users currently connected to the
                                network. The broker then displays that list to Bob, who can then select the
                                desired file from the list and open a direct link with Alice’s computer,
                                which currently has the file. The download of the actual file takes place
                                directly from Alice to Bob.



                                5
                                 According to LimeWire LLC, the developer of a popular file-sharing program, Gnutella was
                                originally designed by Nullsoft, a subsidiary of America Online. The development of the
                                Gnutella protocol was halted by AOL management shortly after the protocol was made
                                available to the public. Using downloads, programmers reverse-engineered the software
                                and created their own Gnutella software packages.
                                (http://www.limewire.com/index.jsp/p2p)




                                Page 22                                                     GAO-03-351 File-Sharing Programs
Appendix II: Description of File Sharing and
Peer-to-Peer Networks




The broker model was used by Napster, the original peer-to-peer network,
facilitating mass sharing of copyrighted material by combining the file
names held by thousands of users into a searchable directory that enabled
users to connect with each other and download MP3 encoded music files.
The broker model made Napster vulnerable to legal challenges6 and
eventually led to its demise in September 2002.

Although Napster was litigated out of existence and its users fragmented
among many alternative peer-to-peer services, most current-generation
peer-to-peer networks are not dependent on the server/broker that was the
central feature of the Napster service, so, according to Gartner,7 these
networks are less vulnerable to litigation from copyright owners.

In the decentralized model, no brokers keep track of users and their files.
To share files using the decentralized model, Ted starts with a networked
computer equipped with a Gnutella file-sharing program, such as KaZaA or
BearShare. Ted connects to Carol, Carol to Bob, Bob to Alice, and so on.
Once Ted’s computer has announced that it is “alive” to the various
members of the peer network, it can search the contents of the shared
directories of the peer network members. The search request is sent to all
members of the network, starting with Carol, who will each in turn send
the request to the computers to which they are connected, and so forth. If
one of the computers in the peer network (say, for example, Alice’s) has a
file that matches the request, it transmits the file information (name, size,
type, etc.) back through all the computers in the pathway towards Ted,
where a list of files matching the search request appears on Ted’s
computer through the file-sharing program. Ted will then be able to open a
connection with Alice and download the file directly from Alice’s
computer.8

One of the key features of Napster and the current generation of
decentralized peer-to-peer technologies is their use of a virtual name space
(VNS). A VNS dynamically associates user-created names with the Internet
address of whatever Internet-connected computer users happen to be




6
A&M Records v. Napster, 114 F.Supp.2d 896 (N.D. Cal. 2000).
7
Lydia Leong, “RIAA vs.Verizon, Implications for ISPs,” Gartner (Oct. 24, 2002).
8
 LimeWire, Modern Peer-to-Peer File Sharing over the Internet.
(http://www.limewire.com/index.jsp/p2p)




Page 23                                                GAO-03-351 File-Sharing Programs
Appendix II: Description of File Sharing and
Peer-to-Peer Networks




using when they log on.9 The VNS facilitates point-to-point interaction
between individuals, because it removes the need for users and their
computers to know the addresses and locations of other users; the VNS
can, to certain extent, preserve users’ anonymity and provide information
on whether a user is or is not connected to the Internet at a given
moment.10

The file-sharing networks that result from the use of peer-to-peer
technology are both extensive and complex. Figure 5 shows a map or
topology of a Gnutella network whose connections were mapped by a
network visualization tool.11 The map, created in December 2000, shows
1,026 nodes (computers connected to more than one computer) and 3,752
edges (computers on the edge of the network connected to a single
computer). This map is a snapshot showing a network in existence at a
given moment; these networks change constantly as users join and depart
them.




9
 S. Hayward and R. Batchelder, “Peer-to-Peer: Something Old, Something New,” Gartner
(Apr. 10, 2001).
10
 Peer-to-peer users may appear to be but are not anonymous. Law enforcement agents
may identify users’ Internet addresses during the file-sharing process and obtain, under a
court order, their identities from their Internet service providers.
11
 Mihajlo A. Jovanovic, Fred S. Annexstein, and Kenneth A. Berman, Scalability Issues in
Large Peer-to-Peer Networks: A Case Study of Gnutella, University of Cincinnati Technical
Report (2001). (http://www.ececs.uc.edu/~mjovanov/Research/paper.html)




Page 24                                                 GAO-03-351 File-Sharing Programs
                                           Appendix II: Description of File Sharing and
                                           Peer-to-Peer Networks




Figure 5: Topology of a Gnutella Network




                                           Page 25                                        GAO-03-351 File-Sharing Programs
              Appendix III: Comments from the Department of Justice
Appendix III: Comments from the
Department of Justice




              Page 26                                                 GAO-03-351 File-Sharing Programs
Appendix III: Comments from the Department of Justice




Page 27                                                 GAO-03-351 File-Sharing Programs
Appendix III: Comments from the Department of Justice




Page 28                                                 GAO-03-351 File-Sharing Programs
                      Glossary
Glossary


Broadband             Operating at bandwidths markedly greater than that provided by telephone
                      networks. Broadband networks can carry digital videos or a massive
                      quantity of data simultaneously. In the on-line environment, the term is
                      often used to refer to Internet connections provided through cable or DSL
                      (digital subscriber line) modems.


BearShare             A file-sharing program for Gnutella networks. BearShare supports the
                      trading of text, images, audio, video, and software files with any other user
                      of the network.


Broker                In the peer-to-peer environment, an intermediary computer that
                      coordinates and manages requests between client computers.


Cartoon pornography   Images of cartoon characters engaged in sexual activity.


Chat                  Internet program enabling users to communicate through short written
                      messages. Some of the most popular chat programs are America Online’s
                      Instant Messenger and the Microsoft Network Messenger. See instant
                      messaging.


Child erotica         Sexually arousing images of children that are not considered
                      pornographic, obscene, or offensive.


Client-server         A networking model in which a collection of nodes (client computers)
                      request and obtain services from a server node (server computer).


Gnutella              A file-sharing program based on the Gnutella protocol. Gnutella enables
                      users to directly share files with one another. Unlike Napster, Gnutella-
                      based programs do not rely on a central server to find files.


Gnutella protocol     Decentralized group membership and search protocol, typically used for
                      file sharing. Gnutella file-sharing programs build a virtual network of
                      participating users.




                      Page 29                                        GAO-03-351 File-Sharing Programs
                            Glossary




Hypertext language          The standard language (HyperText Markup Language) used to display
(HTML)                      information on the Web. It uses tags embedded in text files to encode
                            instructions for formatting and displaying the information.


Instant messaging (IM)      A popular method of Internet communication that allows for an
                            instantaneous transmission of messages to other users who are logged into
                            the same instant messaging service. America Online’s Instant Messenger
                            and the Microsoft Network Messenger are among the most popular instant
                            messaging programs (see chat).


Internet relay chat (IRC)   Internet chat application allowing real-time conversations to take place via
                            software, text commands, and channels. Unlike the Web-based IM, IRC
                            requires special software and knowledge of technical commands (see
                            chat).


IP address                  Internet Protocol address. A number that uniquely identifies a computer
                            connected to the Internet to other computers.


KaZaA                       A file-sharing program using a proprietary peer-to-peer protocol to share
                            files among users on the network. Through a distributed self-organizing
                            network, KaZaA requires no broker or central server like Napster.


LimeWire                    A file-sharing program running on Gnutella networks. It is open standard
                            software running on an open protocol, free for the public to use.


Morpheus                    A file-sharing application using the KaZaA peer-to-peer protocol to share
                            files among users on the network.


Morphing                    A process whereby one image is gradually transformed into a second
                            image.


MP3                         Moving Pictures Experts Group (MPEG) MPEG-1 Audio Layer-3. A widely
                            used standard for compressing and transmitting music in digital format
                            across Internet. MP3 can compress file sizes at a ratio of about 10:1 while
                            preserving sound quality.


                            Page 30                                       GAO-03-351 File-Sharing Programs
             Glossary




Newsgroups   Discussion groups on Usenet, varying in topic from technical to bizarre.
             There are over 80,000 newsgroups organized by major areas or domains.
             The major domains are alt (any conceivable topic, including pornography);
             biz (business products and services); rec (games and hobbies); comp
             (computer hardware and software); sci (sciences); humanities (art and
             literature); soc (culture and social issues); misc (miscellaneous, including
             employment and health); and talk (debates on current issues). See Usenet.


Node         A computer or a device that is connected to a network. Every node has a
             unique network address.


Peer         A network node that may function as a client or a server. In the peer-to-
             peer environment, peer computers are also called servents, since they
             perform tasks associated with both servers and clients.


Server       A computer that interconnects client computers, providing them with
             services and information; a component of the client-server model. A Web
             server is one type of server.


SETI@home    Search for extraterrestrial intelligence at home. A distributed computing
             project, SETI@home uses data collected by the Arecibo Telescope in
             Puerto Rico. The project takes advantage of the unused computing
             capacity of personal computers. As of February 2000, the project
             encompassed 1.6 million participants in 224 countries.


Topology     The general structure—or map—of a network. It shows the computers and
             the links between them.


Usenet       A bulletin board system accessible through the Internet containing more
             than 80,000 newsgroups. Originally implemented in 1979, it is now
             probably the largest decentralized information utility in existence (see
             newsgroups).

Virtual      Having the properties of x while not being x. For example, “virtual reality”
             is an artificial or simulated environment that appears to be real to the
             casual observer.



             Page 31                                       GAO-03-351 File-Sharing Programs
                           Glossary




Virtual name space (VNS)   Internet addressing and naming system. In the peer-to-peer environment,
                           VNS dynamically associates names created by users with the IP addresses
                           assigned by their Internet services providers to their computers.


World Wide Web             A worldwide client-server system for searching and retrieving information
                           across the Internet. Also known as WWW or the Web.




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                           Page 32                                      GAO-03-351 File-Sharing Programs
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