The way you described it is pretty accurate. Basically the Pakistani government issued an order to all ISPs that operate in the country to block access to YouTube due to some content in a clip that was available on the site. PCCW, a global ISP based in Hong Kong, complied with the order a bit too efficiently, allowing the updated routing information to leak outside of Pakistan and into the rest of their network and across to other peering partners of theirs, affecting YouTube access worldwide. Once a YouTube engineer noticed and called it in PCCW fixed their systems to only advertise it in Pakistan.

A similar effect could happen to any web site, as long as you can get someone with reasonably high level access in an ISP to participate in the effort. Generally that requires that you're a government or that you have some very good friends in very high places. For a reasonably intersting recount of a cyber-attack on a county and how global ISPs can manage and deflect the attack (a similar but not 100% comparable event) there's a pretty good Wired article that you can read about an attack on the Estonian infrastructure by what is presumed to be Russian mafia.

A couple important things to note from all this:

• Despite the redundant routing structure, countries are able to isolate themselves on the internet
• It is very possible for an ISP to break a lot of things if they aren't careful
• Your geography on the Internet isn't anonymous

S.