This is yet another reason to use ebay for your transactions. Ebay requires a credit card number, and, at least in theory, a real name and address of a real person. Armed with more information like this, you can better chase down and prosecute the rip off artists.
As mentioned before, though, be legal about it and who knows, you might even wind up with more money.
Gil
(Still, dropping a cement-filled toilet onto this turd's windshield at 2 AM would be devilishly satisfying.... )
...just keep it in the realm of idle fantasy!