If you happened to be searching for a video at YouTube.com Sunday afternoon, there's a good chance your browser told you it was unable to locate the entire Web site. Turns out, much of the world was blocked from getting to YouTube for part of the weekend due to a censorship order passed by the government of Pakistan, which was apparently upset that YouTube refused to remove digital images many consider blasphemous to Islam.
According to wire reports, Pakistan ordered all in-country Internet service providers (ISPs) to block access to YouTube.com, complaining that the site contained controversial sketches of the Prophet Mohammed which were republished by Danish newspapers earlier this month. The people running the country's ISPs obliged, but evidently someone at Pakistan Telecom - the primary upstream provider for most of the ISPs in Pakistan - forgot to flip the switch that prevented those blocking instructions from propagating out to the rest of the Internet.
To understand how a decision by bureaucrats in Islamabad could prevent the rest of the world from accessing arguably one of the Web's most popular destinations, it may first help to accept the basic notion that when the Internet was designed decades ago, everyone on the network pretty much knew and trusted one another. While the close-knit family of individuals responsible for keeping the Internet humming along has since grown into a larger community, it is still a fairly small community based largely on trust and everyone playing nice with one another.
So, what happened? From everything I've read and heard, the YouTube situation appears to have been due to an innocent -- if inept -- mix-up, which allowed Pakistan's ISPs to effectively announce to the world that its Internet addresses were the authoritative home of YouTube.com, and for about an hour or so, most of the rest of the world's ISPs incorporated those updated directions as gospel.
(ISPs manage Internet traffic coming in and out of their networks using expensive hardware devices called routers. Most ISPs have a set of routers that manage the traffic within their network, and a separate set of routers designed to hand off traffic to and from the larger Internet.)
In a country where the government more or less can tell resident ISPs what to do, blocking citizens from visiting certain sites is simple: The ISPs simply tell their customers that if they're looking for a censored site, they either receive an empty page or are redirected to wherever the ISP or government deems as an appropriate substitute destination.
But, if those same ISPs allow their internal blocking instructions to propagate out to their externally-facing routers - the ones that communicate with the wider Internet - such actions can have far-reaching implications, as we saw with YouTube on Sunday