How was the PlayStation Network hacked, though? Ironically, for security reasons, and because Sony is historically very tight-lipped on such matters, we will probably never know the exact attack vector -- but we can certainly make some well-educated guesses about how the PlayStation Network was hacked. First, given its proximity to Anonymous's recent attacks, it's likely that the database breach is somehow related. It's safe to assume that Anonymous could have learned about a weakness in the PSN's security mechanisms, and then passed that data on to another group of hackers -- and from there, if the hole was big enough, the attackers might have been able to simply step right in with an SQL injection attack.
The other alternative is the recent release of a custom PlayStation 3 firmware build called Rebug, which effectively turns a PS3 into a developer unit and activates a slew of features that consumers can not normally access. Most significantly, though, the Rebug firmware gives your console trusted access to Sony's internal developer network. There are reports that once you're on the internal, trusted network, a whole range of new hacks became available, including the use of faked credit card details on the PlayStation Network.
With the custom firmware installed, it's possible that customer details database -- the one that was breached -- became easily accessible. It's possible that Sony's security mechanisms simply didn't account for an internal attack from a trusted network -- and indeed, you can't create a functional network without having some trusted agents.
