What is likely to have happened here is that the FBI seized the server as evidence for a copyright infringement violation. These blogs were hosted on this server and are therefore no longer available.
When you host your blog on a free site, you get what you pay for. If you were thinking ahead, you have kept a backup on your own system and now can go find a reputable host for your blog.
Correct. Typically though, a simple cease and desist order is sent. The hosting company deletes out the offending material and the other 72,999 sites are unaffected.
This is like chopping off your leg to remove pimple.