According to Sony, there was a small breach of some of the user accounts on Playstation Network(PSN), Sony Entertainment Network (SEN), and Sony Online Entertainment. The press release states that actions were taken to ensure the compromised accounts have been locked as well as by notifying the users of the breaches.
"Less than one tenth of one percent of our PSN, SEN and SOE consumers may have been affected. There were approximately 93,000 accounts (PSN/SEN: approximately 60,000 accounts; SOE: approximately 33,000) where the attempts succeeded in verifying those accounts’ valid sign-in IDs and passwords, and we have temporarily locked these accounts."
It seems like despite having been made an example of several times in the past year by hackers, Sony has still been unable to ensure their user accounts will remain safe. With online gaming becoming more prevalent and new systems hopefully being announced by Sony and Microsoft in the next year, it seems like Sony really needs to get their act together if they are going to be able to ensure their customers' security.
For the more details from the press release, please head over to Sony (Tokyo)