There was a report of credit card fraud, I believe in August 2008, on the Warden's message of the US Embassy page in the DR. Credit card info was being stolen by some crooks abroad that had tapped into the line that credit card machines use.
Last year, I had my ATM card cloned and my PIN stolen. I was unable to figure out where this happened. I had used my ATM card at the ATM in Playero in mid September. Two weeks later, I was back in the US and used it at a 7-11 store in Virginia. It wasn't until end of October that I noticed, when someone made two large withdrawals from my checking account in a bank in Canada.