The BBC has an intriguing article about a man who is selling Ultima Online virtual goods for a living. Near the end, they talk about his ethical dilemma in dealing in stolen UO goods:
Mr Dibbell greatest fear is that he falls prey to real cyber criminals who pillage his Ultima items or steals the cash from his PayPal account.
I’m pretty sure PayPal has reasonable protections, but in UO someone could just come along and bump off his character. Eventually, you might see people band together to police areas to prevent crime. There is, after all, a reason (or many reasons) why society is what it is today.