The PlayStation Network has been down for five days, frustrating gamers and leaving Sony with a big problem on its hands.

On Saturday, Sony said that it is working to rebuild part of its systems to bolster its network security. Sony took its PSN and Qrocity entertainment services offline on Wednesday night.

On Friday, the company issued a statement saying that the downtime is due to an “external intrusion,” which many have interpreted to mean a denial-of-service attack. A similar statement had appeared on the company’s EU blog, but was taken down.

Many had suspected Anonymous, the loosely organized hacktivist group, was responsible for the problems, having launched attacks against the PSN earlier this month. On Friday, Anonymous Operations released a statement titled “For Once, We Didn’t Do It,” saying that it had nothing to do with the problems, though the group did say that a smaller group may be acting on its own.

Sony did not immediately respond to a request for comment.

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