Not being able to play PSP games that you purchased through PSN is Sony's fault (whether they want to blame SCEA or SCEI, whichever is more convenient), not Anon's. If you read anything, you'll see they haven't gone after the PSN service because they don't intend to harm Sony's consumers.
"Anonymous is not attacking the PSN at this time. Sony’s official position is that the PSN is undergoing maintenance. We realize that targeting the PSN is not a good idea. We have therefore temporarily suspended our action, until a method is found that will not severely impact Sony customers. "
So, once again, it's Sony's **** up, just like everything else.