After you check in, the room phone rings, allegedly from the front desk. There's a problem with your credit card
, the operator says, please give me the account numbers again. To pull it off, all a criminal has to do is trick their way through a hotel switchboard and catch a patron in the room. If you get a call like this, hang up, call the operator, and ask if there's a problem. That's a good habit at home, too. Hang up and call back. If there's really a problem, don't reveal your number over the phone. Just walk back to the front desk.