Hundreds of users of the UK iTunes Store got their accounts hacked with account credit and credit card information stolen on Wednesday (Feb 8th). The case came to Apple's knowledge when multiple users reported on the user forum the incident with their accounts.
The user forums had claims from dozens of users saying they not only had their store credit spent, but also spotted fraudulent activity on the PayPal accounts associated with their Apple ID. Apple issued an statement saying the problem was "isolated" failing to acknowledge any sort of breaches in their system.
Apple has said they will be refunding all the users who got their store credit stolen and to those who might also have had their personal information leaked, the company issued an apology letter. Apple advises those who feel vulnerable to change passwords.