It emerged last night that a custom firmware hack may have been the reason Sony took PSN completely offline last week, a move which has kept the service offline ever since.
While links to the firmware running have been posted on YouTube and links have been circulating for days, a "moderator" from PSX-Scene last night posted on Reddit to claim that the software had allowed hackers unlimited access to retail PSN content via fake credit card numbers.
The firmware essentially turns a retail PS3 into a dev kit, and makes PSN believe the machine is part of Sony's developer network. As it's a trusted party, the network then fails to check details such as credit card numbers, meaning those using the hack were able, apparently, to download as much content from PSN's retail servers as they liked.
According to that post, developers have now been told that "only 3.60+ debug firmwares will be allowed on the dev network anymore. All earlier versions will be cut. If you want to retain your access you need to contact Sony and upgrade to 3.60 debug firmware."
While we're told it's true that hackers gained access to PSN retail content through this hack, it is not at all confirmed that this was the reason Sony took PSN offline last Wednesday.
Sony's developer and retail networks are independent - theoretically meaning the developer network could be closed down, leaving the retail network in action - and patching out the firmware in question is supposedly trivial.
Sony said last week that PSN has been taken offline thanks to an "external intrusion".
We'll ask Sony for comment.