First published: 27th February 2008
Acting in concert with Pakistan's government and Pakistan Telecom, Hong Kong's largest ISP, PCCW blocked worldwide access to the popular YouTube video-sharing website for over an hour early Monday morning, Hong Kong time. Two mistakes were blamed for the problem.
The incident occurred after the Pakistan Telecommunications Authority, acting on a policy set by the Pakistan Ministry of Information Technology, instructed ISPs in Pakistan to block YouTube because, "of videos depicting humiliation of the Prophet that were blasphemous in nature" last Friday. Pakistan Telecom implemented the ban by adding a rule to their routers that directed traffic to the YouTube IP address range to a black hole. The first mistake was that the rule used a more specific address range than that used by YouTube itself. The BGP routing protocol therefore regarded the new rule as the "best route" to YouTube, which should be propagated to other routers. The second mistake was that PCCW, Pakistan Telecom's ISP, blindly trusted the information provided by their routers and PCCW propagated the route to the rest of the world.
The problem was fixed when the rules were corrected by the ISPs. The Pakistan Telecommunications Authority has since lifted its ban on YouTube. There have been no reports of economic devastation due to the lack of access to cute, silly, badly focussed and irreligious videos.