If it is the same, I have to wonder what Fifa is doing that makes it possible. Never bought the "social engineering" line that was used to explain it before.
Accounts being compromised doesn't necessarily mean Sony have been hacked. There are many (far easier) ways to gain access to an account that wouldn't involve a network-wide breach.
FIFA is one of the only ways to convert an account into real money by selling it, and alongside COD just happens to be one of the most popular games. This is also why you see a lot of European accounts compromised due to FIFA being popular here. If COD had an incentive for making real money it would be used instead of FIFA.
When the Chinese were selling PSN accounts loaded with $150 a few years back on DHgate they were selling for $10-15. Point is the download library or even wallet balance doesn't bring in much, but the FIFA card mode (forget its name) has you cashing out larger sums. There's plenty of more eloquently described summarisations of how FIFA makes money all over Google.
I'm pretty sure its to do with the fantasy points and cards being tradeable. So you can nab someone's account, buy a ton of what you want on FIFA and then transfer those points or cards to another account. Essentially piggy backing virtual goods that have a monetary value. At this point you can now charge Joe Bloggs online $40 for the Messi card Sony want $50 for, and he's actually giving you money to your PayPal account. Loading up hundreds of dollars in a PSN wallet is no use to a hacker, they can't cash it out, so need to find a way to get money into their own banks/hands.