The idea of Coin is simple but elegant: replacing several payment cards with single card-like sophisticated device. The technology behind Coin is pretty impressive, but there is security concern. Normally, when carders want to use the stolen card data in order to make a purchase in brick-and-mortar store, they need to produce the fake plastic card, which looks like a real credit card, and encode it with the stolen magnetic tracks. However, technological revolution comes to the carders world. With Coin, there is no need to produce a good looking physical plastic anymore. The stolen data can be encoded directly into the Coin device. There is one obstacle that must be overcome - taking the picture of the real card when entering the new card information into Coin through the iPhone or Android app. But I think that generating a realistic image of the credit card (so it could be photographed instead of the real card) is cheaper than creating a physical counterfeited card which requires special equipment such as PVC-printer, embosser, tipper, etc. (more details about this process can be found in my new book - Hacking Point of Sale - which is being published by Wiley).