Credit card compromised

Has anyone's credit card been compromised in the last few days? Mine was. And why does this have anything to do with poker?
Because I haven't used this card in over a year. I haven't lost my credit card or been a victim of phishing. I've used it to deposit money on about 8-9 poker sites. Some of them have questionable reputations, like jackpoker and juicystakes. So it seems to me that this is related to the leakage of sensitive information from some poker site. I know that the deposit should be provided by a third party, but on many of these sites I enter my credit card details directly to their clients and send them a copy of my credit card for verification.