Letter: Combating credit card fraud with technology

Two years ago I had dinner in a sushi restaurant: the server takes my credit card on a plastic tray, brings me my receipt — to which I add gratuity — then my card and final receipt are left for me on the tray. The following afternoon, I get a call from my credit card company asking me about several charges to online sites, iTunes, Amazon, etc. They were comparing my purchases to my purchasing history and, seeing discrepancies, called for verification. Together we determined the legit