It's been a few years since I've dealt with credit card verification, and even then only peripherally, but the information needed to prove to the credit card clearing houses that you are you is pretty slim. Basically, they just use all the numerical information in your address slapped together. That is, if you live at 123 Elm St, Apt 54; Anywhere, NC 27587, then the only information they need is 12354 and 27587 (they keep the zip separate so that they can deal with zip and zip+4 without issue). I forget how fractions work, but, basically that's it. So all a thief needs to know is your address, and they could figure that out by looking in the phone book, once they have your name and CC number.