Hmmm, well I think the situation is complicated by the simple fact that there are internet "hacktivists" who are trying to use the Anonymous name as an umbrella for their activities.
While 4 years old now, consider this message from Anonymous in response to Fox News:
http://www.youtube.com/watch?v=RFjU8bZR19A
Now compare that attitude, and what we've seen with kids like Jessi Slaughter, to the wikileaks fiasco, and the current attacks on Sony. I'll also point out that a lot of sites that were sort of connected to Anonymous, at least by reputation, like Encyclopedia Dramatica, have been changing their stripes as well, I suspect because of the attention the more high profile internet antics of Anonymous have been getting, with successful attacks against goverments, and businesses.
It wouldn't surprise me if Anonymous *IS* responsible for the attacks on PSN and Sony, given that they don't make promises. Of course it can also be argued that they said they weren't letting it go, and really we haven't seen any real damage done to the users, just potential damages which are reflecting on Sony. There is also the distinction that Sony itself has taken the services down apparently, as opposed to them being knocked offline through DDOS attacks. To a certain way of thinking, it can be argued that even though Anonymous doesn't keep promises as a general rule, it might be keeping this one. That said, it DOES seem odd that Anonymous would have hidden files in the code, rather than be making a spectacle out of the thing.
It's also possible that there isn't Anonymous, the MO seems more akin to what older groups in the spirit of "Legion Of Doom" or "Masters Of Deception" might have done.
I'm being contridictory and rambling, but the bottom line is that we don't actually know anything.
Also I'll be honest, to me The Internet is about freedom, and truthfully I think that trumps the need for the security desired by businesses. Sony went online, and decided to be a douche on an unprecedented level in the way it shut off advertised features of it's consoles, honestly I think getting what they deserve is actually a benefit of the internet, where in other aspects of society, they would have gottn away with this unscathed simply due to being a rich multi-national corperation. This doesn't make Anonymous morally right, but it does make Sony's plight unsympathetic.