RETAILING: Thumbs Down

Each year bad-check passers fleece U.S. businesses of an estimated $4 billion—far more than bank robbers get with guns. Using stolen or bogus drivers' licenses and other faked identification, "paper hangers" have found merchants—who are naturally anxious to ring up sales and cannot easily verify such fakes—especially easy targets. And even if checkbook bilkers are later caught, convictions are hard to get because many suspects cannot be identified to the satisfaction of courts. Now two new devices on the market are enabling stores to record identification that even the cleverest forger cannot fake: his thumbprint. The systems cannot prevent the...