PlayStation outage allegedly caused by ‘hacking attack’

The company said that it has now taken the PSN down voluntarily while it investigated an "external intrusion". Users trying to connect are being met with error messages stating that the network is "undergoing maintenance" or is "suspended".

The PlayStation Network has more than 70 million accounts registered worldwide, and is used by owners of PS3 and PlayStation Portable machines to download games, films and music, as well as to play online with friends.

Sony says that it has been targeted by hackers’ group Anonymous – a largely ‘faceless’ collective hack-tivist group that has no formal structure or organisation.

The group’s core has however refuted responsibility. In a message posted on the AnonOps blog, it said "for once we didn't do it". However, it suggested that some members may have acted on their own without the group's knowledge.

Anonymous has been critical of the Japan-based entertainment giant over its treatment of George Hotz, an American hacker who unlocked the PS3's closed operating system.

Sony filed a lawsuit against the 21-year-old, arguing that his hack had allowed pirated games to be played on the machine.

The case was dropped earlier this month after Hotz agreed to an injunction banning him from similar behaviour in future.

In denying responsibility for the attack, Anonymous said: "A more likely explanation is that Sony is taking advantage of Anonymous' previous ill-will towards the company to distract users from the fact that the outage is actually an internal problem with the company's servers."

In a blog post, the company thanked users for their patience and assured them that it was working "around the clock" to strengthen the network infrastructure.

"Though this task is time-consuming, we decided it was worth the time necessary to provide the system with additional security," wrote Patrick Seybold, the company's senior director of corporate communications and social media.

The statement however did not address issue of whether hackers could have obtained access to personal information, including credit card details, stored by PSN.