At the moment I wouldn't be surprised if there is a few people just 'saying' they can sell you details, but they are actually just full of ****.
Let's be honest. Right now is the best time for someone to stand up and say "Hey guys! I'm the one that hacked the PSN and can get you credit card numbers!" The person either has a number of card to sell already, or they just sell you a bunch of random numbers.
Seriously, I'm surprised people like that aren't taken out easily.
Officer in charge of taking douches like that out: "I'll accept your offer, how much?" "*this much*" "Ok fine" *Pays*
Then spend some time tracking that money where it goes. "Oh, it was sent to *that account*, *look into details of that account* got withdrawn at an ATM/Bank in *this area* and the original account was created *by person, at location, at time*" Sure some of that stuff can be faked, but it at least gives a starting location