I didn't read most of this thread, but the fact that people don't know what's going on and can't be arsed to google it before posting in here is making me angry. Let me just quickly tell you why the hackers are doing this.
George Hotz (aka 'geohot'), hacker of iPhones and Playstation 3's, released codes online that would let PS3 users "jailbreak" their consoles; that is to say, it would allow them to run third-party programs on it. Sony didn't like this and eventually forced geohot to take the codes offline. A group, either Anonymous or otherwise, hacked Sony in defense of "free speech".
They aren't cyber-terrorists, really. For one, not one single use of fraudulent credit card use has been reported. No odd activities either. I think Sony is just getting what they deserve, really. And to all of you affected, Sony is giving you a crapload of free stuff anyway, so just relax already.