Editing HTTP 404 (section)

=== Intentional 404s ===
In July 2004, the UK telecom provider [[BT Group]] deployed the [[Cleanfeed (content blocking system)|Cleanfeed]] content blocking system, which returns a 404 error to any request for content identified as potentially illegal by the [[Internet Watch Foundation]].<ref>{{cite web |url=https://publicaffairs.linx.net/news/?p=154 |title=LINX Public Affairs » Cleanfeed: the facts |publisher=Publicaffairs.linx.net |date=10 September 2004 |access-date=6 March 2011 |archive-url=https://web.archive.org/web/20110513071912/https://publicaffairs.linx.net/news/?p=154 |archive-date=13 May 2011 |url-status=dead}}</ref> Other ISPs return a [[HTTP 403]] "forbidden" error in the same circumstances.<ref>{{cite web|url=https://airbrake.io/blog/http-errors/403-forbidden-error|title=DEMON – Error 403|access-date=14 June 2012}}</ref> The practice of employing fake 404 errors as a means to conceal [[censorship]] has also been reported in [[Thailand]]<ref>{{cite news|last=Sambandaraksa|first=Don|date=18 February 2009|title=The old fake '404 Not Found' routine - Dead link|newspaper=Bangkok Post|url=http://www.bangkokpost.com/tech/technews/11872/the-old-fake-404-not-found-routine|access-date=12 September 2010}}</ref> and [[Tunisia]].<ref>{{cite web |url=http://opennet.net/node/950 |title=Tunisian journalist sues government agency for blocking Facebook, claims damage for the use of 404 error message instead of 403 |first=Helmi |last=Noman |date=12 September 2008 |publisher= Open Net Initiative |access-date=21 November 2010}}</ref> In Tunisia, where censorship was severe before the [[Tunisian Revolution|2011 revolution]], people became aware of the nature of the fake 404 errors and created an imaginary character named "[[Ammar 404#Censorship during the Ben Ali regime|Ammar 404]]" who represents "the invisible censor".<ref>{{cite web|date=27 May 2010|title=Anti-censorship movement in Tunisia: creativity, courage and hope!|url=http://advocacy.globalvoicesonline.org/2010/05/27/anti-censorship-movement-in-tunisia-creativity-courage-and-hope/|access-date=28 August 2010|publisher=Global Voices Advocacy}}</ref>