If you sell enough stuff online at sites like Craigslist and eBay, eventually you will receive an offer for your wares that far exceeds your asking price. Such offers are often the first stage of a scam in which the fraudster sends a counterfeit check along with some elaborate explanation for offering such a high amount. The scam artist then asks the seller to wire back the difference after the check is deposited. It should surprise no one that the checks always bounce, leaving anyone who falls for the scam liable to their bank for the entire amount. This is not a new scam, but I had never seen one of these fake checks in person until my colleague here at washingtonpost.com – Dan – recently received one of these fairly official-looking checks after advertising an $800 bike frame for sale on Craigslist.com. The outer envelope was hand addressed with