He's, allegedly, the one who made the leak public. Yes. But that data was leaking for a long time and we have no way of knowing who else collected it.

If I had thought Sony was secure I'd actually be better off now, with my card visibly leaked, than before where only the bad guys had access to it. If my card was fraudulently used I'd have been in a bad position before the leak was known - I'd be assumed to be a criminal until I proved that I didn't make the purchases. After the leak became public I'd be more likely to get reasonable treatment from my credit card company.