The Internet security crisis confronting PlayStation Network users has gotten worse than expected as Sony revealed on Monday additional 25 million clients stolen by hackers. Reuters

With the PlayStation Network outage now in its sixth day, Sony has finally admitted what most have suspected: The hackers that compromised the system also stole personal data.

In a message to PlayStation Network and Qriocity subscribers, Sony confirms that a bevy of data was stolen in the intrusion. Although we are still investigating the details of this incident, we believe that an unauthorized person has obtained the following information that you provided: name, address (city, state, zip), country, email address, birthdate, PlayStation Network/Qriocity password and login, and handle/PSN online ID, read the message.

Less certain is the status of credit card information, which Sony says may have also been compromised. While there is no evidence at this time that credit card data was taken, we cannot rule out the possibility, the company said.

A password and login will get an intruder access to the user's account details, including the credit card payment information. Unfortunately, users won't be able to change any of it until the system comes back up. On the bright side, it's possible that a hacker who got the logins and passwords won't be able to use them either. The PlayStation Network serves 70 million users. An attack on users' credit card information is a significant one.

Still unknown is the identity of the attackers. Sony said in its message to subscribers that it believes an unauthorized person was to blame. Suspicions initially fell on the hacker collective Anonymous. The group, which has taken aim at Sony multiple times in recent months, denied official involvement in the take down last week, but it could not rule out that members had not worked independently. While it could be the case that other Anons have acted by themselves, AnonOps was not related to this incident and does not take responsibility for whatever has happened, Anonymous said.

Regardless of who was to blame, Sony finally gave estimates for when the services would return. We have a clear path to have PlayStation Network and Qriocity systems back online, and expect to restore some services within a week, wrote Sony Communications Director Patrick Seybold on the PlayStation blog.