According to a self-proclaimed PSX-Scene moderator on Reddit, however, credit card numbers are involved but not necessarily in a way that users need to worry about.
Calling himself Chesh420, the moderator wrote that a new custom PS3 firmwave called Rebug was released on March 31. Rebug apparently turns standard PlayStation 3 consoles into semi-developer units, which among other things and with a little bit of effort allows hacked consoles to be put back online. But a few bright folks over at NextGenUpdate also figured out that because consoles with this firmware installed have access to Sony's private developer network, credit card information isn't checked for validity; in other words, they could gain unlimited download access with fake card numbers.
"What happened next was extreme piracy of PSN content," he wrote. "Sony, realizing the issue here, shut down the network. Now, before you go freaking out about the latest information posted about Kotaku, no one's personal information was accessible via this hack. Not to say they couldn't get it, but no one is admitting to it being available.
It's purely speculation at this point, although Chesh420 claimed that someone with official access to Sony's developer network stated that the company put out a warning today that only debug firmware versions 3.60 and newer will be allowed on the network from this point on. He also posted a four-part timeline backing up his story.
1.)Rebug was released on 3/31/11.
2.)First guides of how to use the dev network to get back on COD games on 4/3/11.
3.)Word of "shady" sites finding a way to pirate PSN content via the dev networks on 4/7/11 (basing this on posts I had to delete on the website).
4.)PSN goes down on 4/20/11"