For those of you who think of credit card theft as a high-tech crime performed online by e-savvy thieves, credit card shaving may sound SO 20th century. But it works -- depending, as usual, on the inattentiveness of store clerks.
Credit card shaving depends on glue and razor blades as much as stealth and the Internet. First, the shaver either finds an valid credit card number by entering various number combinations in an online store until one clicks, or buys lists of valid card numbers from the black market. The crook then carefully shaves embossed numbers from the surface of gift cards, as well from a defunct Visa, MasterCard or the like credit card. He then glues the number of the valid card onto the credit card blank, effectively creating for himself a duplicate of the valid credit card.
Then, the shaver need only scratch the mag strip so that the clerk will be required to enter the number manually, and he's ready to go shopping.
You are probably thinking, "Wouldn't you be able to tell that the card had been altered?" The answer is, yes, you probably could, but the clerk who has a line of impatient customers glaring at him and faces no penalty for accepting the card has little incentive to act as a fraud detector.
This is yet another argument for signing up for online access to your credit card account, so that you can check expenditures more frequently than once a month. The whole world has access to glue and razor blades.