Child abuse image content list

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The child abuse image content list (CAIC List) is a list of URLs and image hashes provided by the Internet Watch Foundation to its partners to enable the blocking of child pornography & criminally obscene adult content in the UK and by major international technology companies.

Contents

Launched by BT as Cleanfeed in July 2004, [1] as of 2009[ needs update ] the list covered 98.6% [2] of UK internet connections. Cleanfeed was temporarily extended to block Newzbin [3] until this process was moved to ISP-specific programmes. In October 2013, the UK government announced that as part of anti-terrorist measures it is considering a similar technology to block "extremist" material [4] [5] [6]

History

Cleanfeed is a content blocking system technology implemented in the UK by BT, Britain's largest Internet provider. It was created in 2003 and went live in June 2004. [1] BT spokesman Jon Carter described Cleanfeed's function as "to block access to illegal Web sites that are listed by the Internet Watch Foundation", and described it as essentially a server hosting a filter that checked requested URLs for Web sites on the IWF list, and returning an error message of "Web site not found" for positive matches. [7] [8] [9] Cleanfeed is a silent content filtering system, which means that Internet users cannot ascertain whether they are being regulated by Cleanfeed, facing connection failures, or the page really does not exist.

By the beginning of 2006, Cleanfeed was used by 80% of Internet service providers. [10] By the middle of 2006, the government reported that 90% of domestic broadband connections were either currently blocking or had plans to by the end of the year. Home Office minister Alan Campbell pledged that all ISPs would block access to child abuse websites by the end of 2007 [11] and UK Home Office Minister Vernon Coaker instructed all UK ISPs to implement a version of Cleanfeed by the end of 2007 on a voluntary basis, or face legal compulsion. [12] However, no legislation was ever introduced and ISPs are still free to join on a voluntary basis. [13] Despite the target for 100% coverage being set for the end of 2007, [14] by the middle of 2008 the proportion of consumer broadband connections that were covered was only 95%. [15] In February 2009, the Government said that it is looking at ways to cover the final 5%. [16] A report in March 2014 by the Culture, Media and Sport Committee reported 98.6% [17] of domestic broadband lines are subject to blocking arrangements.

The Internet Watch Foundation used to [18] also take reports about racial hatred from the public and IT professionals until 2011. This content is not included in the IWF URL list supplied to the online industry for blocking purposes.

CAIC targets only alleged child sexual abuse content identified by the Internet Watch Foundation. In June 2011 the Motion Picture Association began court proceedings in an attempt to force BT to use Cleanfeed to block access to NewzBin2, a site indexing downloads of copyrighted content. [19] BT was ordered to block access to the site in late July [3] and in a later clarification, BT was given two weeks to implement the block starting at the end of October. [20] The case ( Twentieth Century Fox Film Corp & Ors v British Telecommunications Plc [2011]) [21] only compels BT's ISP division to implement the block on NewzBin, it remains outside of remit of the IWF URL list which is strictly limited to blocking sites which host child sexual abuse content. [22]

In August 2015 the IWF announced it was to begin sharing the list with tech giants Facebook, Google, Twitter and Yahoo to block contents being distributed through their networks.[ citation needed ]

Technical implementation

The confidential url hash blacklist contains URLs of pages (not whole sites) to be blocked. A less confidential list of sites potentially containing blocked pages is available to ISPs. Routers on the edge redirect traffic to these sites to special HTTP proxy servers which perform the actual filtering by matching HTTP requests to URLs on the blacklist. Traffic that does not match the specific URL is forwarded through the proxy filter.

Chapter 7 of a research paper by Richard Clayton [23] provides an overview of the Cleanfeed technology.

The routers at an ISP that has implemented Cleanfeed technology check traffic destination against a list of IP addresses of sites that are suspected of hosting filtered traffic. If there is no match, the traffic is directed to the content host:

URL Filtering (1).svg

If the site IP address is found in the list of suspected sources of unwanted material, the traffic is routed to proxies (highlighted as IWF proxies) [24] that check the specific page against a confidential blacklist of pages.

URL Filtering (2).svg

This two-pass implementation reduces the load on the proxy servers by not requiring that all traffic pass through them.

Technical detection

Due to the filtering mechanism, to detect whether a site is being filtered via an individual ISP's connection, one must first capture the filtering servers IPs by running traceroute for the first few hops to some websites known to be blocked [23] [25]

In the example below, the IP addresses in bold are the ISP filtering servers.

Demon Internet were the only ISP to notify users routinely when content is blocked and offer the option to intercept and serve filtered content over https connections. [26]

Filtering comparison

The other popular way of blocking content is DNS manipulation. Compared to this, Cleanfeed has the following properties:

The first UK survey of Internet regulation was carried out in 2007 and 2008. [28] [29] 90.21% of the participants in the limited scale survey were unaware of the existence of CleanFeed; of those who had heard about it, only 14.81% percent understood it completely. 11.1% learned about CleanFeed from UK government statements, and 22.2 percent from BT's statements. 60.87% did not trust BT, and 65.22% did not trust IWF to be responsible for a silent content blocking system in the UK.

A majority of the participants preferred an open content blocking system targeting child abuse content, rather than no Internet regulation. More specifically, 65.2% would prefer to see a message stating that a given site was blocked, 57.3% would like to have access to a form for unblocking a given site, and 68.5% would prefer more frequent briefing by BT, IWF and the UK.

Criticism

One of the criticisms of Cleanfeed is its lack of transparency. This is a consequence of the list of blocked sites being secret. There are no safeguards to stop sites unrelated to child pornography being added to the list as a result of policy changes. [19] It thus has a potential for the censorship of materials outside of its original remit. Indeed, the Home Office in the UK has previously indicated that it has considered requiring ISPs to block access to articles on the web deemed to be "glorifying terrorism", within the meaning of the new Terrorism Act 2006, saying: "our legislation as drafted provides the flexibility to accommodate a change in Government policy should the need ever arise." [30] This has led some to describe Cleanfeed as the most perfectly invisible censorship mechanism ever invented and to liken its powers of censorship to those employed currently by China. [31] However, at present no legislation is in place, and the implementation of the IWF URL list is still a voluntary agreement between ISPs and the IWF.

The measures have also been criticised for being inadequate as they only block accidental viewing and does not prevent content delivered through encrypted systems, file sharing, email and other systems. [32]

Another criticism is that Newzbin claims to have successfully circumvented Cleanfeed following a court order forcing BT to censor the website over copyright infringement claims. [33] [34] This poses the question as to whether websites hosting child pornography could adopt similar measures to allow their users access to blocked content.

Due to the proxy server implementation of the Cleanfeed system, websites that filter users by IP address such as wikis and file lockers will be significantly broken through the system, [35] even if only a tiny proportion of its content is blocked.

Finally, information has surfaced that suggests that Cleanfeed could potentially be manipulated to provide a blacklist of blocked websites. [36] [37] This is problematic as it could allow the dissemination of child pornography, rather than the prevention of access to it. Again this has led some to question Cleanfeed as a successful system for blocking illegal internet content.

See also

Wikipedia internal

Related Research Articles

An Internet filter is software that restricts or controls the content an Internet user is capable to access, especially when utilized to restrict material delivered over the Internet via the Web, Email, or other means. Such restrictions can be applied at various levels: a government can attempt to apply them nationwide, or they can, for example, be applied by an Internet service provider to its clients, by an employer to its personnel, by a school to its students, by a library to its visitors, by a parent to a child's computer, or by an individual user to their own computers. The motive is often to prevent access to content which the computer's owner(s) or other authorities may consider objectionable. When imposed without the consent of the user, content control can be characterised as a form of internet censorship. Some filter software includes time control functions that empowers parents to set the amount of time that child may spend accessing the Internet or playing games or other computer activities.

<span class="mw-page-title-main">Proxy server</span> Computer server that makes and receives requests on behalf of a user

In computer networking, a proxy server is a server application that acts as an intermediary between a client requesting a resource and the server providing that resource. It improves privacy, security, and possibly performance in the process.

A Domain Name System blocklist, Domain Name System-based blackhole list, Domain Name System blacklist (DNSBL) or real-time blackhole list (RBL) is a service for operation of mail servers to perform a check via a Domain Name System (DNS) query whether a sending host's IP address is blacklisted for email spam. Most mail server software can be configured to check such lists, typically rejecting or flagging messages from such sites.

Various anti-spam techniques are used to prevent email spam.

Internet censorship in Australia is enforced by both the country's criminal law as well as voluntarily enacted by internet service providers. The Australian Communications and Media Authority (ACMA) has the power to enforce content restrictions on Internet content hosted within Australia, and maintain a blocklist of overseas websites which is then provided for use in filtering software. The restrictions focus primarily on child pornography, sexual violence, and other illegal activities, compiled as a result of a consumer complaints process.

SORBS was a list of e-mail servers suspected of sending or relaying spam. It had been augmented with complementary lists that include various other classes of hosts, allowing for customized email rejection by its users.

<span class="mw-page-title-main">OpenDNS</span> Domain name system provided by Cisco using closed-source software

OpenDNS is an American company providing Domain Name System (DNS) resolution services—with features such as phishing protection, optional content filtering, and DNS lookup in its DNS servers—and a cloud computing security product suite, Umbrella, designed to protect enterprise customers from malware, botnets, phishing, and targeted online attacks. The OpenDNS Global Network processes an estimated 100 billion DNS queries daily from 85 million users through 25 data centers worldwide.

Cleanfeed is the name given to various privately administered ISP level content filtering systems operating in the United Kingdom and Canada, and as of May 2012 undergoing testing in Australia with a view to future mandatory implementation. These government-mandated programs originally attempted to block access to child pornography and abuse content located outside of the nation operating the filtering system.

<span class="mw-page-title-main">Internet censorship</span> Legal control of the internet

Internet censorship is the legal control or suppression of what can be accessed, published, or viewed on the Internet. Censorship is most often applied to specific internet domains but exceptionally may extend to all Internet resources located outside the jurisdiction of the censoring state. Internet censorship may also put restrictions on what information can be made internet accessible. Organizations providing internet access – such as schools and libraries – may choose to preclude access to material that they consider undesirable, offensive, age-inappropriate or even illegal, and regard this as ethical behavior rather than censorship. Individuals and organizations may engage in self-censorship of material they publish, for moral, religious, or business reasons, to conform to societal norms, political views, due to intimidation, or out of fear of legal or other consequences.

WebMinder was a content blocking system implemented in the UK by Brightview Internet Services and used on their ISPs such as Madasafish, Global Internet and Waitrose.Com. It was similar in purpose to Cleanfeed, BT's blocking system and used a list from the Internet Watch Foundation. In addition to this it claimed to stop images from these sites being transmitted as email attachments.

Internet censorship in the United Kingdom is conducted under a variety of laws, judicial processes, administrative regulations and voluntary arrangements. It is achieved by blocking access to sites as well as the use of laws that criminalise publication or possession of certain types of material. These include English defamation law, the Copyright law of the United Kingdom, regulations against incitement to terrorism and child pornography.

Censorship in Denmark has been prohibited since 1849 by the Constitution:

§ 77: Any person shall be at liberty to publish his ideas in print, in writing, and in speech, subject to his being held responsible in a court of law. Censorship and other preventive measures shall never again be introduced.

DNS hijacking, DNS poisoning, or DNS redirection is the practice of subverting the resolution of Domain Name System (DNS) queries. This can be achieved by malware that overrides a computer's TCP/IP configuration to point at a rogue DNS server under the control of an attacker, or through modifying the behaviour of a trusted DNS server so that it does not comply with internet standards.

<span class="mw-page-title-main">Blacklist (computing)</span> Criteria to control computer access

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<span class="mw-page-title-main">Internet Watch Foundation</span> Registered charity in Cambridge, England

The Internet Watch Foundation (IWF) is a global registered charity based in Cambridge, England. It states that its remit is "to minimise the availability of online sexual abuse content, specifically child sexual abuse images and videos hosted anywhere in the world and non-photographic child sexual abuse images hosted in the UK." Content inciting racial hatred was removed from the IWF's remit after a police website was set up for the purpose in April 2011. The IWF used to also take reports of criminally obscene adult content hosted in the UK. This was removed from the IWF's remit in 2017. As part of its function, the IWF says that it will "supply partners with an accurate and current URL list to enable blocking of child sexual abuse content". It has "an excellent and responsive national Hotline reporting service" for receiving reports from the public. In addition to receiving referrals from the public, its agents also proactively search the open web and deep web to identify child sexual abuse images and videos. It can then ask service providers to take down the websites containing the images or to block them if they fall outside UK jurisdiction.

<span class="mw-page-title-main">Internet Watch Foundation and Wikipedia</span> Blacklist of Wikipedia in the UK

On 5 December 2008, the Internet Watch Foundation (IWF), a British watchdog group, blacklisted content on the English Wikipedia related to Scorpions' 1976 studio album Virgin Killer, due to the presence of its controversial cover artwork, depicting a young girl posing nude, with a faux shattered-glass effect obscuring her genitalia. The image was deemed to be "potentially illegal content" under English law which forbids the possession or creation of indecent photographs of children. The IWF's blacklist is used in web filtering systems such as Cleanfeed.

Censorship in Finland refers to government policies in controlling and regulating certain information.

The precise number of websites blocked in the United Kingdom is unknown. Blocking techniques vary from one Internet service provider (ISP) to another with some sites or specific URLs blocked by some ISPs and not others. Websites and services are blocked using a combination of data feeds from private content-control technology companies, government agencies, NGOs, court orders in conjunction with the service administrators who may or may not have the power to unblock, additionally block, appeal or recategorise blocked content.

<span class="mw-page-title-main">Internet censorship and surveillance in Europe</span>

This list of Internet censorship and surveillance in Europe provides information on the types and levels of Internet censorship and surveillance that is occurring in countries in Europe.

References

  1. 1 2 Bright, Martin (6 June 2004). "BT puts block on child porn sites". The Guardian. London. Retrieved 30 April 2010.
  2. ↑ McIntyre, TJ. "Child Abuse images and Cleanfeeds: Assessing Internet Blocking Systems". Research Handbook on Governance of the Internet: 5. Archived from the original on 20 January 2022. Retrieved 26 April 2014.
  3. 1 2 "BT ordered to block links to Newzbin 2 website". BBC News. 28 July 2011.
  4. ↑ "UK.gov's web filtering mission creep". The Register. 29 November 2013.
  5. ↑ "Hansard Oct 23rd 2013 - question 10". Hansard. 13 October 2013.
  6. ↑ "Ministers will order ISPs to block terrorist and extremist websites". The Guardian. 27 November 2013.
  7. ↑ "How net providers stop child porn", BBC News, 7 February 2006. Retrieved 29 May 2006.
  8. ↑ Arnfield, Robin (20 July 2004). "BT Technology Blocks Online Pornography". NewsFactor Network. Archived from the original on 11 December 2008.
  9. ↑ "IWF/BT Project Cleanfeed Archived 24 February 2009 at the Wayback Machine ", Internet Watch Foundation. Retrieved 29 May 2006.
  10. ↑ Paul Goggins (Parliamentary Under-Secretary, Home Office) Commons, 13 February 2006 col. 1130 Internet (child pornography)
  11. ↑ "Home Office clueless: The transcript". Computer Shopper. 17 March 2009. Archived from the original on 21 March 2009.
  12. ↑ "Government sets deadline for universal network-level content blocking". linx.net. Archived from the original on 23 January 2016. Retrieved 12 January 2016.
  13. ↑ Internet Watch Foundation - "URL List". Accessed 12 November 2013
  14. ↑ Vernon Coaker (Parliamentary Under-Secretary, Home Office) Written Answer, 15 May 2006 col. {{{column}}} Child Abuse (Internet)
  15. ↑ Vernon Coaker (Parliamentary Under-Secretary, Home Office) Written Answer, 16 June 2008 col. {{{column}}} Pornography: Internet
  16. ↑ "Online child abuse images warning". BBC News. 23 February 2009. Retrieved 5 May 2010.
  17. ↑ "Online safety - Page 16" (PDF). parliament.uk. Retrieved 19 March 2014.
  18. ↑ "Incitement to racial hatred removed from IWF's remit". iwf.org.uk. Archived from the original on 13 November 2011. Retrieved 12 January 2016.
  19. 1 2 "Film-makers seek injunction to block pirate site". BBC News. 28 June 2011. Retrieved 28 June 2011.
  20. ↑ "UK ISP BT Given 14 Days To Block Newzbin2". TorrentFreak. 26 October 2011. Retrieved 31 October 2011.
  21. ↑ [2012] 1 All ER 806, [2012] Bus LR 1471, [2011] RPC 28, [2011] EWHC 1981 (Ch)
  22. ↑ Internet Watch Foundation. IWF.org.uk. Blocking Good Practice Archived 26 July 2013 at the Wayback Machine . Accessed 12 November 2013
  23. 1 2 Clayton, Richard (November 2005). "Anonymity and traceability in cyberspace" (PDF). Richard Clayton. Retrieved 10 December 2008.
  24. ↑ Hogge, Becky. "IWF censors Wikipedia, chaos ensues". Open Rights Group. Archived from the original on 19 April 2009. Retrieved 10 December 2008.
  25. ↑ "Check The IWF list". lightning-bolt.net.
  26. ↑ McIntyre, T J. "Child Abuse images and Cleanfeeds: Assessing Internet Blocking Systems". Archived from the original on 20 January 2022. Retrieved 6 May 2014.
  27. ↑ Steve Crocker, Shinkuro, Inc.; David Dagon, Georgia Tech; Dan Kaminsky, DKH; Danny McPherson, Verisign, Inc.; Paul Vixie; Internet Systems Consortium (2011). "Security and Other Technical Concerns Raised by the DNS Filtering Requirements in the PROTECT IP Bill" (PDF).{{cite web}}: CS1 maint: multiple names: authors list (link)
  28. ↑ "Internet regulation: The need for more transparent Internet filtering systems and improved measurement of public opinion on Internet filtering - Koumartzis - First Monday". firstmonday.org. Archived from the original on 21 October 2012. Retrieved 12 January 2016.
  29. ↑ Book: BT's Cleanfeed and Online Censorship in UK, N Koumartzis, London College of Communication (University of the Arts London)
  30. ↑ "Government sets deadline for universal network-level content blocking Archived 1 June 2006 at the Wayback Machine ", LINX, 29 May 2006. Retrieved 29 May 2006.
  31. ↑ Professor Lilian Edwards, University of Southampton. "From child porn to China, in one Cleanfeed". Archived from the original on 16 May 2013. Retrieved 26 April 2014.
  32. ↑ "Restricting All but the Predators", Dark Reading, 14 June 2006. URL accessed on 24 June 2006.
  33. ↑ "Newzbin claims BT block 'not working'". BBC News. 3 November 2011. Retrieved 12 January 2016.
  34. ↑ Mark Jackson. "Banned Piracy Website Expands BT Circumvention Tool to Include The Pirate Bay". ispreview.co.uk. Retrieved 12 January 2016.
  35. ↑ "Six UK ISP's block a Wikipedia article locking out Wikipedia edits". bitterwallet.com. Archived from the original on 2 December 2013. Retrieved 12 January 2016.
  36. ↑ Failures in a Hybrid Content Blocking System
  37. ↑ SA Mathieson (26 May 2005). "Back door to the black list". the Guardian. Retrieved 12 January 2016.
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