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Cleanfeed is a content blocking system implemented in the UK by BT, Britain's largest Internet provider, which targets only illegal content identified by the Internet Watch Foundation. All UK ISPs will be obliged to implement a version of it by the end of 2007. Information on how this works is restricted to members of industry organisation LINX. [1] [2] Another system used by different ISPs is WebMinder. [3] Image File history File links This is a lossless scalable vector image. ... DansGuardian blocking whitehouse. ... BT Group plc (formerly British Telecommunications plc) which trades as BT (pronounced Bee tee) (also previously as British Telecom and is still commonly known as such amongst the general public) is the privatised UK state telecommunications operator. ... About the IWF The Internet Watch Foundation (IWF) was formed in 1996 following an agreement between the government, police and the internet service provider industry that a partnership approach was needed to tackle the distribution of child abuse images (often referred to as child pornography) online. ... ISP may mean: Internet service provider, an organization that offers users access to the Internet and related services. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... Linx AB was a joint venture between the Swedish railway, SJ, and the Norwegian railway NSB. It operated fast trains Oslo-Stockholm and Oslo-Göteborg-København. ... WebMinder is a content blocking system implemented in the UK by Brightview Internet Services and used on their ISPs such as Madasafish, Global Internet and Waitrose. ...

Cleanfeed was created in 2003 and went live in June 2004. [4]

The Internet Watch Foundation's aims include criminally obscene content and content that incites racial hatred. It is unknown whether images meeting those criteria are blocked by Cleanfeed.

Technical implementation

There is a blacklist containing URLs to be blocked. Using Border Gateway Protocol (BGP) servers on the backbone routes traffic to IP addresses that match domains that appear in URLs in the blacklist to special HTTP proxy servers. These proxy servers then do the actual filtering by matching HTTP requests to URLs on the blacklist. A blacklist is a list or register of entities who, for one reason or another, are being denied a particular privilege, service, or mobility. ... A Uniform Resource Locator, URL (spelled out as an acronym, not pronounced as earl), or Web address, is a standardized address name layout for resources (such as documents or images) on the Internet (or elsewhere). ... The Border Gateway Protocol (BGP) is the core routing protocol of the Internet. ... This article does not cite any references or sources. ...

Filtering comparison

The other popular way of blocking content is DNS manipulation. Compared to this, Cleanfeed has the following properties: It has been suggested that this article be split into multiple articles. ...

• Harder to circumvent. But still not that hard. Users can use proxy servers. Servers can use another port than 80.

• 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. E.g., it would be possible to block only one image in an article.

See also

• Content-control software
• Internet censorship

DansGuardian blocking whitehouse. ... Countries where the free flow of information is restricted. ...

External links

• Richard Clayton: Anonymity and traceability in cyberspace" Cambridge Tech Report. Ch 7 deals extensively with Cleanfeed.