Cleanfeed (content blocking system)

For other uses, see Cleanfeed (disambiguation).

Cleanfeed is the name given to privately administered ISP level content filtering systems operating in the United Kingdom and Canada. It is also the name of a proposed mandatory Australian ISP level content filtering system which is undergoing testing. These government mandated programs originally attempted to block access to child abuse/pornography content located outside of the nation operating the filtering system. In the UK, its use has now been extended to block websites that link to copyrighted material.^[1]

United Kingdom

Cleanfeed is a content blocking system implemented in the UK by BT, Britain's largest Internet provider, which (as of 2008) targets only alleged child sexual abuse content identified by the Internet Watch Foundation. UK Home Office Minister Vernon Coaker instructed all UK ISPs to implement a version of it by the end of 2007 on a voluntary basis, or face legal compulsion.^[2]

Cleanfeed was created in 2003 and went live in June 2004.^[3]

As well as child sexual abuse content hosted around the world, the Internet Watch Foundation also takes reports from the public and IT professionals via its internet Hotline regarding criminally obscene content and content that incites racial hatred, hosted in the UK. This content is not included in the IWF URL list supplied to the online industry for blocking purposes.

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.^[4] BT was ordered to block access to the site in late July^[1] and in a later clarification, BT was given two weeks to implement the block starting at the end of October. ^[5]

Technical implementation

There is a blacklist containing URLs to be blocked. Routers on the edge redirect traffic to IP addresses that match domains that appear in URLs on the blacklist to special HTTP proxy servers. These proxy servers then 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^[6] provides an overview of the Cleanfeed technology.

In an ISP that has implemented Cleanfeed technology, the routers at the ISP will validate traffic destination against a list of IPs that are suspected of hosting filtered traffic. In the case of no match, the traffic continues as normal to the content host:

In the case that the IP address is found in the list of suspected sources of unwanted material, the traffic is routed to proxies (highlighted as IWF proxies)^[7] that then verify the specific destination against a more specific blacklist.

This two-pass implementation reduces the load on the proxy servers, and does not require that all traffic pass through the filtering proxies.

Filtering comparison

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

• Slightly harder to circumvent, although users can use Open proxys, or Tor (anonymity network), servers can use another port than 80, or HTTPS.
• Less collateral damage. DNS based blocking is criticized for blocking all content on a site with the same domain name. Cleanfeed only blocks what is explicitly blacklisted. For example, it would be possible to block only one image in an article.

Related Surveys

According to a survey conducted in a small number of participants in 2007-8 ^[8] "90.21% of all the participants were unaware of the existence of Cleanfeed software (this percentage was 61.95% for UK based internet users living in UK for more than 4 years). From the few that have heard about Cleanfeed software before their participation in the survey, only 14.81% were deeply aware of it, while few have learnt about it by official statements of the participating bodies (11.1% from UK government’s statements and 22.2% of BT’s statements).

What’s more, 60.87% of the participants don’t trust BT and 65.22% don’t trust IWF either to be responsible for a silent censorship model in UK. The majority of the participants prefer an open censorship model targeting child abuse content rather no internet censorship at all. So, 65.2% of all the respondents would like to see a message stating that the website is blocked, 57.3% stated they would like to have access to a requesting form for unblocking a website and 68.5% that they would like to see a better and more frequent informing by BT, IWF and UK government."

Australia

Further information: Internet censorship in Australia#Policy of compulsory internet filtering

Cleanfeed in Australia is a proposed mandatory ISP level content filtration system. It was proposed by the Beazley led Australian Labor Party opposition in a 2006 press release, with the intention of protecting children who were vulnerable due to claimed parental computer illiteracy.^{[citation needed]} It was announced on 31 December 2007 as a policy to be implemented by the Rudd ALP government, and initial tests in Tasmania have produced a 2008 report. Cleanfeed is funded in the current budget, and is moving towards an Expression of Interest for live testing with ISPs in 2008. Public opposition and criticism have emerged, led by the EFA and gaining irregular mainstream media attention, with a majority of Australians reportedly "strongly against" its implementation.^[9] Criticisms include its expense, inaccuracy (it will be impossible to ensure only illegal sites are blocked) and the fact that it will be compulsory. Cleanfeed is a responsibility of Senator Stephen Conroy's portfolio.

Canada

Cleanfeed in Canada is a voluntary Internet URL filtering list maintained by Cybertip.ca for use by participating ISPs.^[10] Eight major providers, representing approximately 80% of Canada's Internet users, have been using the list since November 2006 to block foreign websites.^[11][12][13]

Accessing child pornography online is illegal in Canada. Cybertip.ca is recognized by the federal government, provincial governments and domestic law enforcement agencies for its expertise in assessing the likely illegality of alleged child pornography online. The Cleanfeed system, however, does not log access to URLs on the list as it is not a law enforcement tool.

Criticisms of Cleanfeed

One of the criticisms of the use of Cleanfeed is its potential for censorship. The lack of transparency regarding the use of Cleanfeed have lead some to question how much control ISPs and government bodies could have over internet content within the countries of its use.^[14] Another criticism is that not only can Cleanfeed be circumvented ^[15][16], but it could also potentially be manipulated to provide a blacklist of blocked websites ^[17][18]. This could allow the dissemination of child pornography, rather than the prevention of access to it.

See also

• Content-control software
• Golden Shield Project
• Internet censorship

References

1. ^ ^{a b} http://www.bbc.co.uk/news/technology-14322957
2. ^ https://publicaffairs.linx.net/news/?p=497
3. ^ Bright, Martin (6 June 2004). "BT puts block on child porn sites". The Guardian (London). http://observer.guardian.co.uk/uk_news/story/0,6903,1232422,00.html. Retrieved 30 April 2010. 
4. ^ "Film-makers seek injunction to block pirate site". BBC News. 28 June 2011. http://www.bbc.co.uk/news/technology-13927335. Retrieved 28 June 2011. 
5. ^ "UK ISP BT Given 14 Days To Block Newzbin2". TorrentFreak. 26 October 2011. http://torrentfreak.com/uk-isp-bt-given-14-days-to-block-newzbin2-111026/. Retrieved 31 October 2011. 
6. ^ Clayton, Richard (November 2005). "Anonymity and traceability in cyberspace". Richard Clayton. Richard Clayton. http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-653.pdf. Retrieved 10 December 2008. 
7. ^ Hogge, Becky. "IWF censors Wikipedia, chaos ensues". Open Rights Group. http://www.openrightsgroup.org/2008/12/08/iwf-censors-wikipedia-chaos-ensues/. Retrieved 2008-12-10. 
8. ^ Koumartzis, Nikolaos (October 2008). "BT's Cleanfeed and Online Censorship in UK". Nikolaos Koumartzis. London College of Communication(University of the Arts London). http://public.bay.livefilestore.com/y1pgG-_yBmT-KwBwHCybxAS8HI2uQGgiWEMt2bqtA0GXDCtfSgPNOYLtMXf6THajAMrK7YZS93BioI9UupiDiY-Qg/cleanfeed_edition1.pdf.zip?download. Retrieved 28 January 2010. ^{[dead link]}
9. ^ Liebhardt, John (2008-12-11). "Australia rallies to “Stop the Clean Feed”". Global Voices Online. http://globalvoicesonline.org/2008/12/11/australia-rallies-to-stop-the-clean-feed/. Retrieved 2008-12-11. 
10. ^ Cleanfeed Canada
11. ^ ISPs and Tipline Step Up Battle Against Internet Child Exploitation
12. ^ Mountie hopes web initiative could cut child abuse
13. ^ ISPs to monitor child porn under proposed bill
14. ^ From child porn to China , in one Cleanfeed
15. ^ Newzbin claims BT block 'not working'
16. ^ Banned Piracy Website Expands BT Circumvention Tool to Include The Pirate Bay
17. ^ Failures in a Hybrid Content Blocking System
18. ^ Back door to the black list

External links

• Internet Watch Foundation
• Richard Clayton: Anonymity and traceability in cyberspace" Cambridge Tech Report. Ch 7 deals extensively with Cleanfeed.
• Nikolaos Koumartzis: BT's CleanFeed and Online Censorship in UK: Improvements for a more secure and ethically correct system" MA thesis, London College of Communication, University of the Arts London.
• BBC News: Doubts over web filtering plans