My listing in Applewood, then one in Arvada, were hijacked for a rental scam

It has become common for Nigerian scammers to post rental offers on homes they don't own.  It seems that they find homes for sale online, then advertise them for rent at half the market value (e.g., $600 per month).  When you reply to their posting, you get this story about how they took a sudden job as a missionary in West Africa or some such lie, and they can't show you the house.  You're asked to fill out a rental application and send them two month's rent (by Western Union or Moneygram) and they'll then send you the keys.  The rental application provides enough information for identity theft on top of losing your money. This scam has been attempted on enough of my listings (four in the last year or so, two in the last two weeks) that I created a small sign that says "NOT FOR RENT" to hang from my yard sign as soon as I get the first call from a would-be renter who was smart enough to call me. I also ask the would-be renter to find the posting again and flag it as a scam.  I don't know if anyone actually fell victim to this scam, but would like to hear from anyone who has! Note: When you click on any posting on craigstlist, the following warning appears in a yellow box above the posting: "Beware any arrangement involving Western Union, Moneygram, wire transfer, or a landlord/owner who is out of the country or cannot meet you in person."  Too bad most people don't notice that warning...