Sony is facing a £250,000 penalty for what is deemed a 'security failure' during the PlayStation Network hack that affected 77 million accounts in April 2011.

The Information Commissioner's Office (ICO) stated that the attack was preventable, and that there was "no disguising that Sony is a business that should have known better".

Sony is now preparing an appeal, in order to reverse the ruling.

"PlayStation Europe notes that the ICO recognises Sony was the victim of 'a focused and determined criminal attack' and that 'there is no evidence that encrypted payment card details were accessed', and that 'personal data is unlikely to have been used for fraudulent purposes'."

Sony chief executive, Kaz Hirai apologized for the security breach one month after the attack brought the entire network down.