The security breach that has had Sony's Playstation Network out of commission for five days now turns out to be of the worst kind, and it involves 70 million subscribers. Far from the hacker's prank suspected last week, it appears the network has been down because Sony turned it off after somebody got in and acquired a whole bunch of user data. That my include credit card information.

On its Playstation blog today, the company said the breach had happened sometime between April 17 and 19, and it had shut down gaming as part of its response. It said whoever got into the network acquired users names, addresses, e-mail addresses, birthdates, passowords, login information, and possibly purchase histories and billing addresses, as well as security answers. Most sinister, however, the post notes that "While there is no evidence at this time that credit card data was taken, we cannot rule out the possibility.... out of an abundance of caution we are advising you that your credit card number (excluding security code) and expiration date may have been obtained."

There's still no clear culprit, either. As we noted last week, Anonymous posted a denial on its own site, stating, "for once we didn't do it." The group's Facebook page still carries posts that suggest it may be involved (or at least not disappointed at the hack), but there's nothing claiming responsibility. The most recent such note went up on Monday:

Remember the glorious days of gaming? when you didn`t see similarities in games and some games were not just copies of another game? when the gaming community did not depend on online gaming and was not infected with "internet tough guys" talking about how they gangbanged your mom last night? These are the times meant to cleanse the world and make people realize how much they`ve been missing out on.

CNBC talked to some experts, who said they didn't think the breach would hurt Sony's stock to badly. However, if customers don't think they can safely play networked games through the Playstation Network, that will definitely hurt the company. Meanwhile, if you're one of 70 million subscribers to the network, it's definitely time to start being very cautious about identity theft.