I dunno why they're blocked here, but clicking on the link results in an error page "this site can not be viewed in your country." I do know that US Congress recently started investigating internet censorship and how various internet companies have been participating with other country's law enforcement and censorship activities. Maybe google is trying to make a point, or maybe the dept of State Security (seig heil!) thought that google china was doing such a great job, they should start doing that sort of thing here.
I wonder why this hasn't hit slashdot or CNN...