History and Law
The Government of Pakistan some years back established the Pakistan Internet Exchange, or PIE, as a means to monitor all incoming and outgoing Internet traffic from Pakistan. The primary purpose of PIE is to filter content as the Government deems fit. A secondary purpose is to keep track of all incoming and outgoing e-mails, which by parliamentary order are kept for a period of at least 3 months.
The Pakistan Telecommunication Company (PTCL) announced in April, 2003 that it would be stepping up censorship of pornographic websites. "Anti-Islamic" and "blasphemous" sites were also censored. In early March 2004, the Federal Investigation Agency (FIA) ordered Internet service providers (ISPs) to block access to all pornographic content. The ISPs, however, displayed absence of technical know-how, and advocated that the PTCL would be better fit to carry out FIA's requirement. A Malaysian firm was then hired to provide a filtering system.
Currently, there is no established law as to which websites the government censors, or when. For past few years, mainly pornographic and anti-establishment political websites have been blocked. Once in a while, western news sites have also been blocked, though these blocks were usually short-lived.
Supreme Court directive
The Supreme Court on March 1, 2006 directed the government to block internet sites displaying sacrilegious cartoons and called for an explanation from authorities as to why these sites had not been blocked earlier [1]. A three-member bench headed by Chief Justice Iftikhar Muhammad Chaudhary, summoned the country's Attorney General as well as senior communication ministry officials on March 13 to give a report of "concrete measures for implementation of the court's order."
On March 2, 2006, in pursuant to a Petition filed by Dr. Mohammed Imram Uppal under Article 184(3) of the Constitution of Pakistan, the Supreme Court sitting en banc ordered the Pakistan Telecommunications Authority (PTA) and other government departments to adopt measures for blocking websites showing blasphemous content. The Court also ordered Attorney General Makhdoom Ali Kahn to explore laws which would enable blocking objectionable websites. In announcing his decision, Chief Justice Iftikhar Muhammad Chaudhry, said, "We will not accept any excuse or technical objection on this issue because it relates to the sentiments of the entire Muslim world. All authorities concerned will have to appear in the Court on the next hearing with reports of concrete measures taken to implement our order," which was scheduled on March 13, 2006.
Consequently, the government blocked a number of websites hosting the sacrilegious cartoons. This ban included all the weblogs hosted at the popular blogging service blogger.com, as some bloggers had put up copies of the cartoons – particularly many non-Pakistani blogs.
On the hearing on March 14, 2006, the PTA informed the Supreme Court that all websites displaying sacrilegious cartoons have been blocked. The bench issued directions to Attorney General of Pakistan Makhdoom Ali Khan to assist the court on Monday on how it could exercise jurisdiction to prevent the availability of blasphemous material on websites the world over [2].
Block of Baloch Nationalist Sites
Pakistan Telecommunication Authority (PTA) on March 25, 2006 blocked access to four Baloch websites carrying material about Baloch nationalists sites. According to BBC, The PTA cited “misinformation” as the reason for banning the websites. The banned sites are:
In the same letter, the PTA has also blocked a Hindu site, http://wwww.hinduunity.com, that is very hostile towards Muslims.
Some argue that this shows the government is going beyond blocking blasphemous websites.
How Internet censorship is imposed
The government of Pakistan currently has a simplistic IP based filtering procedure in place, and since all websites hosted on blogspot resolve to the same IP address, they all have been blocked.
Since the PIE uses Cisco routers to block traffic, which are capable of more complex filtering rules, it is expected that the government will remove this blanket block on all blogspot weblogs in the near future and only target specific ones.
As all internet traffic is routed through the PIE, Pakistani ISPs have also been ordered to also block certain websites on their routers. Currently, all the major ISPs in Pakistan are blocking weblogs hosted at blogspot.com.
See also
Media Reports
Others
Workarounds
Digital Opportunity Initiative for Pakistan
Government Policies Relating to Internet Censorship
As of 6th May, 2006, the Pakistani government has once again put a ban on Blogspot. This has been confirmed by numerous bloggers across Pakistan.

The banned blogs can now be accessed through an alternative sites such as  PKBlogs.com - Blogspot Proxy and other proxy servers.



Since the morning of May 2, 2006, the blanket ban on the blogspot.com blogs has been lifted. This has been confirmed by various people on the  'Action Group Against Blogspot Ban In Pakistan' mailing list. The six baloch and plenty of Indian sites are still blocked.

The website was originally blocked because some of the blogs it hosted, reportedly contained ''"sacrilegious" content'', mostly in the form of cartoons that were earlier published by Jyllands-Posten, and republished in some Blogs. The Supreme Court of Pakistan directed the government of Pakistan to block all websites that contained such content on March 1, 2006.