At first, I was all "Oh, okay. Sucks, that happens all the time. Poor schmucks." This was my initial reaction because I wasn't really affected by the semi-recent PS3 hacking event because I don't have my credit card information there and I'm not all that active in the Steam Forums. It took a few seconds before realizing I've been buying shit off Steam through my credit card for a couple years now.
Though my primary concern is my own credit card security, I'm really hoping that none of the stolen CC details can be used for evil.