Well, whoever is behind the PSN facts, it looks like they weren't dumb enough to leave their names around, so technically they are anonymous :P
We have to admit this trend of giving things general labels is really relaxing. Somebody blows something up, it's Al Qaeda. Somebody "hacks" something, it's Anon. If it wasn't like this, imagine the amount of time journalists (or professional investigators!) should spend doing, OMG, research and even investigation to find the actual causes of things. The stress. The fatigue. (The chance of being laid off if your work doesn't bring results.) So much easier like that: something happens, you have somebody to blame in a matter of minutes.
And this way, it is much easier to hide your own responsibility as well, at least to the general public... only a few will know (or care) about the "hack" being bad password policies and/or overconfidence (I'm looking at you HBGary), poor security, and you know, the usual reasons for "Anonymous's" "hacks".
Side Note: not talking about terrorist attacks here... but the Al Qaeda reference is really appropriate.