In April of that year, hackers stole millions of customers’ data from the PlayStation Network (PSN), as part of a campaign launched by hactivist group Anonymous.

The UK’s data watchdog said today that the breach could have been prevented if Sony had kept its security software up to date and encrypted customer passwords.

“If you are responsible for so many payment card details and log-in details then keeping that personal data secure has to be your priority,” said ICO deputy commissioner and director of data protection David Smith. “In this case that just didn’t happen, and when the database was targeted – albeit in a determined criminal attack – the security measures in place were simply not good enough.”

Sony has rejected the ICO’s accusation. “Sony Computer Entertainment Europe strongly disagrees with the ICO’s ruling and is planning an appeal,” it said in a statement. “Criminal attacks on electronic networks are a real and growing aspect of 21st century life and Sony continually works to strengthen our systems, building in multiple layers of defence and working to make our networks safe, secure and resilient.”

“The reliability of our network services and the security of our consumers’ information are of the utmost importance to us, and we are appreciative that our network services are used by even more people around the world today than at the time of the criminal attack.”