Reading all the bad news on this thread, I'm reminded how amazing it is that most of the time the trading Honor System on so many different forums works so well.
I'm grateful for the smooth and enjoyable transactions I've had with so many different sellers on so many different forums. Paypal is great, and most people deal with integrity.
Thieves are despicable sleazeballs, often mentally ill in obvious ways, and usually live miserable existences. They exploit that law enforcement is busy frying bigger fish and that the court system bureaucracy is designed to pad a lot of pockets but not deliver much 'justice'.
It may be no consolation to the victims that scumbag fraudsters are bottom feeders moving in scumbag circles. Whatever they scam slips right through their fingers to some scumbag roommate, some thieving one night stand or hookup, pawn shop, etc.
Hope this works out. At least posting this thread is a useful warning, and hopefully it will save other people some grief.