[UPDATE] The Sony post is not territory specific as it's also present on the U.S. PlayStation site, so it seems like a global issue.

Original story follows:

In a post on the official PlayStation website in the U.K., Sony Computer Entertainment Europe has warned its customers that "there has been a possibility of unauthorized access to personal information on the PlayStation Store through PCs."

SCEE deems it unlikely but admits that "it is possible that the passwords of a small percentage of PlayStation Network users may have been changed through unauthorized access, making it possible to view users' personal information and/or use the Wallet for the PlayStation Store. PlayStation Network accounts do not display entire credit card numbers, so any unauthorized access to your PlayStation Network account is very unlikely to compromise your credit card number."

"We have taken immediate measures to rectify this issue and system security is restored," Sony continued. "We have investigated the extent of unauthorized access and possible alteration of passwords that could have occurred before corrective measures were taken, and are directly contacting customers who may have been affected by this incident. In order to verify that your account is intact, we strongly suggest that PlayStation Network users sign in to the service. If you can successfully sign in with your pre-set password, your account is not affected by this incident."

Interestingly, this is not the first time that Sony has encountered a security problem with its PlayStation Network. Last October, SCEA revealed to GameDaily BIZ that an IT imposter managed to gain access to customer information on the PlayStation Network. At the time, the company said it should not be considered a breach, however, since the network wasn't technically hacked.