Also, by law, in my utopia if not already, the credit card company is repsonsible for losses due to fraud as long as you report a stolen card promptly. It's up to them whether to believe you right off, but if you report a card as stolen, any transactions timestamped after that report (and the timestamps can be secured, too, by a trusted timestamp server) are Not Your Problem, whether they believed you when you called or had to be convinced later.