You should definitely dispute it. You need to find out the IP address that was used to register, and what information the person had that signed you up. Their may be bigger fish to fry than that website if someone has a lot of your personal information. In a few days you might receive a $12,000 invoice for a motor home, that's what happened to a friend of mine. Turns out, someone got his credit card number and some other personal information while he was at spring break. He hired an investigator, and eventually determind that this hot chick was staying at the resort, posing a fellow student, getting guys really messed up on alcohol and other stuff taking them to her room, having her way with them, and stealing their personal information. There wasn't a lot he could do about it because it was taking place in Mexico, but he was able to get things straightened out over here at least so he didn't ruin his credit.