In a bizarre turn of events, Pakistan "banned" Youtube. This was because Youtube apparently contained "blasphemous content", specifically the reproduction of the Danish cartoons showing Prophet Mohammed. The story turns interesting in the way Pakistan's ISP chose to impose the "ban".
So an ISP in Pakistan decided to announce a route that would re-direct anyone trying to get to YouTube to some other site that probably hosted a warning about the blasphemous content. Results were predictable. YouTube itself disapeared from the Internet, And, I suspect that most of Pakistan is experiencing performance issues as they are receiving ALL of the YouTube requests from around the world. By 2:30 the Internet watch guards had alerted the backbone provider for Pakistan to filter out those malicious route announcements and alerted YouTube to announce more granular routes that would supercede the Pakistani routes, at least in the US.
Someone in PieNet didn't understand BGP and ended up hijacking the IPs of Youtube instead! This results in enormous amount of traffic through Pakistan and as a result, Pakistan itself is hosed from the internet.
The telecom company that carries most of Pakistan’s traffic, PCCW, has found it necessary to shut Pakistan off from the Internet while they filter out the malicious routes that a Pakistani ISP, PieNet, announced earlier today. Evidently PieNet took this step to enforce a decree from the Pakistani government that ISP’s must block access to YouTube because it was a source of blasphemous content.
So what was happened was that the Pakistani ISP started advertising a different IP address for Youtube (to divert their traffic to a different address). But due to the way BGP works, the address change percolated all the ay through and as a result, Youtube's IPs were effectively hijacked. This led to a downtime of more than an hour for Youtube. The traffic through Pakistan was enough to overwhelm its pipes and as a result, most of the traffic to Pakistan was cut off.
I wonder if Google has a case in its hands for getting its IPs hijacked by the pakistani ISP, leading to its website being down for more than an hour worldwide.
On the higher level, One, it is a bad sign if a government can cause such disruption to the internet. Two, the cartoons have been available on the net for a long time. By doing a high profile ban of Youtube (and angering its citizens), the Pakistan government may be trying to take the spotlight away from the election results and its aftermath and the increasing pressure on Musharaf.
1. Renesys Blog has the technical details. Apparently, the new IP prefixes propagated in less than two minutes.
2. According to All Things Pakistan, the censoring was political rather than religious. The videos in question may be those related to election rigging in the recent elections.