Also, the hackers might’ve got access to use the Wallet for the PlayStation Store.
The notice adds that measures have already been taken and the system security was restored:
“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.”
Last but not least, users are reminded that the attack is unlikely to have compromise theirr credit card number, given that PlayStation Network accounts do not display them entirely.