It's a good thing Sony warned people to be vigilant about their credit cards, because as part of the company's Tokyo press conference yesterday PlayStation boss Kaz Hirai said that up to ten million customer's account details could have been compromised.
That's not the personal details on their PSN account - all 77 million of those were up for grabs - that's ten million customer's credit card details. We've known for some time that credit card details have been at risk as part of the attack on the network, but this is the first time Sony has been able to put a figure on the number of card holders potentially affected.
It's important to note that these cards are still potentially at risk: there is still no confirmation that any of these ten million cards' data have been compromised.
While it's been confirmed that CVV2 details - which are requested as part of PSN transactions, but not stored on Sony's servers - were not obtained, it's possible for hackers to obtain the three-digit codes (found on the back of cards) via simple brute force, especially when they have their hands on the rest of the card's details.