I certainly can't say I know the law in this respect. His rant did include the names of a few people which could possibly be bad for them, but it's too late now - it was posted online, cached by lots of spiders, copied by lots of people... Pulling it down now doesn't seem like it'd much matter.
They have a link to the copy at the Smoking Gun, right where it's down; I'd say this was a question of keeping the FBI happy without actually impeding the flow of information.
