In the fantasy world of online gaming a multinational corporation such as Sony would be a lumbering giant locked in a battle to the death with a nimble-footed hero. In the real world, the hackers who have besieged the Japanese group are criminals, not heroes. But Sony’s battle to protect its systems is beginning to look like a nightmare version of its fantasy games.

So far, the hackers are winning. Sony’s reputation for software excellence has been shredded, and personal data relating to millions of customers has been stolen. Its cornerstone online revenue strategy has been imperilled, and its succession plan has been undermined, less than two months after it was announced. Worst of all, the attacks reflect an approach to information security that was at best easy-going and at worst downright negligent.

Sony shut its PlayStation Network two weeks ago after discovering that personal details of its 77m members, including names, dates of birth, e-mail addresses, user IDs and passwords, had been accessed by an unknown hacker. Details of 10m credit cards were also exposed.