Some good news is that banks and credit card companies have gotten very good at protecting consumers against fraud. If you find out that a scammer has your bank account or credit card number, report it to your financial institution immediately. There's a very good chance you will get your money back and you will also pass on some appreciated information that can help stop scammers in their tracks.
It wouldn't hurt to get in touch with your ISP, either. They can clamp down on fraud and alert other providers of the problem.