Mine happened a couple of years ago on Ebay. Seller had a yellow sleeved RMR...didn't appear to be a stolen picture or anything. I paid around $500 or so for it and he only accepted money orders or checks (even had impeccable feedback).
I contacted him by phone and he said a friend hacked into his account and was stealing money from people but assured me I'd get my money back. Kept waiting and calling and finally the negs came pouring in and he wouldn't answer or return phone calls.
Just by pure luck, I googled him and saw him quoted in a newspaper and it mentioned a gas station where he worked. I called the gas station and sure enough it was him. I basically told him to refund my money or I was going to let the owner of the gas station know that he had an employee who was committing theft over the internet.
Thankfully, he took my threat seriously and promptly returned the funds.
"The farther we go, the more the ultimate explanation recedes from us, and all we have left is faith."