All you people saying that the REAL hackers would have never been caught, I ask you this:
Do you think the FBI would REALLY think that the first IP that showed up as the "attacker" would be the person responsible without looking into the possibility that the attack was relayed? I mean you are random internet people, do you not think the FBI does not have people trained to understand this stuff? Why do you think most of these hackers are so young? Because the government and security groups have hired all the older ones.
Pull your heads out of your bums. EVERYTHING CAN BE TRACKED ON THE INTERNET. ANY request you send is logged SOMEWHERE. Sure you relay it through someone, hell maybe even several, but there is evidence that you were there, even if it means cross referencing hundreds or thousands of IP addresses between requests. There is no such thing as anonymity on the internet (even in airports and internet cafes).
ANONYMOUS can do some damage, but US and international laws show that they have the ability to punish these people, and now they are proving they have the skills and know-how to do so.