I had one of these scam jockeys try to pull one off of my old ad. I listed a car, sold it, and the new owner took delivery. The same day the new owner picked it up, I received an e-mail from some guy asking me why I wanted to send the money to Illinois when the car was in Colorado. I told him that it had been sold and the high bidder had just picked up the car. He sent me a copy of the e-mail with the "second chance offer". The ad was identical to mine with the exception of the payment information. The "second chance offer" guy had gotten a cashiers check and was dropping it in the mail when he thought to write me and ask about the address. If he would have gone ahead and mailed it he would have been screwed.
Long story short, we reported everything to ebay and they pulled it within about an hour.
F'ing scumbags!