Probably not related. Consider that 75 million users' information was compromised. Given a sample size that large, it's highly likely that there will be some people in that set who had their credit card compromised in a completely unrelated way.
Given the following:
"The Consumer Sentinel Network (CSN) is a secure online database of millions of consumer complaints available only to law enforcement. In addition to storing complaints to the FTC, the CSN also includes complaints filed with the Internet Crime Complaint Center, Better Business Bureaus, Canada’s Phone Busters, the U.S. Postal Inspection Service, the Identity Theft Assistance Center, and the National Fraud Information Center, among others."
The CSN received 1.2 million complaints in 2008, 62400 of which were specifically credit card fraud.
This means that of the approximately 170 million+ credit card owners in the US, roughly 0.035% of them reported credit card fraud in such a way that CSN saw it. There are likely many more cases that only get reported directly to banks without reaching CSN.
0.035% of 70 million+ users? 24500 people. All of which, due to PSN being an online service, have internet connectivity and are potential blog commenters.
Add to it that you're not going to remember the cases where people say "Nope, I haven't experienced fraud.", you're only going to remember those where people say "Money was stolen from me!"
Unless the reported incidence frequency is above the "normal" / average cases of credit card fraud or someone reports fraud on a card that was proven only to be used with PSN, I would hold off on blaming anyone quite so soon.
OTOH, a good security mindset should probably assume that the attackers will use the ill-gotten data in some malevolent way, not just for lulz.