Harrah's in Tahoe recently had a dealer palm about $800,000 worth of chips! I would have thought eye-in-sky would reveal this sort of thing but apparently not. Tagged chips and a monitor in the employee areas would seem to be the answer. I've made a couple of posts with links to pertinant info in the last couple of weeks if you'd care to do a search for key words "RFID" and "MindPlay".