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Cleanfeed (content blocking system)
Encyclopedia
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.
, 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.
Cleanfeed was created in 2003 and went live in June 2004.
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. BT was ordered to block access to the site in late July and in a later clarification, BT was given two weeks to implement the block starting at the end of October.
containing URL
s 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 server
s. 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 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:
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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) that then verify the specific destination against a more specific blacklist.
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This two-pass implementation reduces the load on the proxy servers, and does not require that all traffic pass through the filtering proxies.
manipulation. Compared to this, Cleanfeed has the following properties:
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."
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. 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. 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.
for use by participating ISPs. Eight major providers, representing approximately 80% of Canada's Internet users, have been using the list since November 2006 to block foreign websites.
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.
United Kingdom
Cleanfeed is a content blocking system implemented in the UK by BTBT Group
BT Group plc is a global telecommunications services company headquartered in London, United Kingdom. It is one of the largest telecommunications services companies in the world and has operations in more than 170 countries. Through its BT Global Services division it is a major supplier of...
, Britain's largest Internet provider, which (as of 2008) targets only alleged child sexual abuse content identified by the Internet Watch Foundation
Internet Watch Foundation
The Internet Watch Foundation is a non-governmental charitable body based in the United Kingdom. It states that its remit is "to minimise the availability of 'potentially criminal' Internet content, specifically images of child sexual abuse hosted anywhere, and criminally obscene adult content in...
. 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.
Cleanfeed was created in 2003 and went live in June 2004.
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
Motion Picture Association
The Motion Picture Association is the international counterpart of the Motion Picture Association of America.-History:The MPA starting out as the Motion Picture Association of America was started in 1922, as a trade organization for American Film industry...
began court proceedings in an attempt to force BT to use Cleanfeed to block access to NewzBin2
NewzBin
Newzbin is a British Usenet indexing website, intended to facilitate access to content on Usenet. The site has caused controversy over its stance on copyrighted material...
, a site indexing downloads of copyrighted content. BT was ordered to block access to the site in late July and in a later clarification, BT was given two weeks to implement the block starting at the end of October.
Technical implementation
There is a blacklistBlacklist
A blacklist is a list or register of entities who, for one reason or another, are being denied a particular privilege, service, mobility, access or recognition. As a verb, to blacklist can mean to deny someone work in a particular field, or to ostracize a person from a certain social circle...
containing URL
Uniform Resource Locator
In computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
s 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 server
Proxy server
In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...
s. 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 provides an overview of the Cleanfeed technology.
In an ISP
Internet service provider
An Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...
that has implemented Cleanfeed technology, the routers at the ISP will validate traffic destination against a list of IPs
IP address
An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...
that are suspected of hosting filtered traffic. In the case of no match, the traffic continues as normal to the content host:
Filtering comparison
The other popular way of blocking content is DNSDomain name system
The Domain Name System is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities...
manipulation. Compared to this, Cleanfeed has the following properties:
- Slightly harder to circumvent, although users can use Open proxyOpen proxyAn open proxy is a proxy server that is accessible by any Internet user. Generally, a proxy server allows users within a network group to store and forward Internet services such as DNS or web pages to reduce and control the bandwidth used by the group...
s, or Tor (anonymity network)Tor (anonymity network)Tor is a system intended to enable online anonymity. Tor client software routes Internet traffic through a worldwide volunteer network of servers in order to conceal a user's location or usage from someone conducting network surveillance or traffic analysis...
, servers can use another port than 80, or HTTPSHttpsHypertext Transfer Protocol Secure is a combination of the Hypertext Transfer Protocol with SSL/TLS protocol to provide encrypted communication and secure identification of a network web server...
. - 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 "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
Cleanfeed in Australia is a proposed mandatory ISP level content filtration system. It was proposed by the BeazleyKim Beazley
In the October 1998 election, Labor polled a majority of the two-party vote and received the largest swing to a first-term opposition since 1934. However, due to the uneven nature of the swing, Labor came up eight seats short of making Beazley Prime Minister....
led Australian Labor Party
Australian Labor Party
The Australian Labor Party is an Australian political party. It has been the governing party of the Commonwealth of Australia since the 2007 federal election. Julia Gillard is the party's federal parliamentary leader and Prime Minister of Australia...
opposition in a 2006 press release, with the intention of protecting children who were vulnerable due to claimed parental computer illiteracy. It was announced on 31 December 2007 as a policy to be implemented by the Rudd
Kevin Rudd
Kevin Michael Rudd is an Australian politician who was the 26th Prime Minister of Australia from 2007 to 2010. He has been Minister for Foreign Affairs since 2010...
ALP government, and initial tests in Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
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
Electronic Frontiers Australia
Electronic Frontiers Australia Inc. is a non-profit Australian national non-government organisation representing Internet users concerned with online liberties and rights...
and gaining irregular mainstream media attention, with a majority of Australians reportedly "strongly against" its implementation. 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
Stephen Conroy
Stephen Michael Conroy is an Australian politician and the current Minister for Broadband, Communications and the Digital Economy in the Gillard Ministry...
's portfolio.
Canada
Cleanfeed in Canada is a voluntary Internet URL filtering list maintained by Cybertip.caCybertip.ca
Cybertip.ca is Canada's official tipline for reporting the online sexual exploitation of children. The tipline is owned and operated by the Canadian Centre for Child Protection, a charitable organization...
for use by participating ISPs. Eight major providers, representing approximately 80% of Canada's Internet users, have been using the list since November 2006 to block foreign websites.
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. Another criticism is that not only can Cleanfeed be circumvented , but it could also potentially be manipulated to provide a blacklist of blocked websites . This could allow the dissemination of child pornography, rather than the prevention of access to it.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