Also check your cards for an RFID chip. If the back of your card has a short "signature strip" it likely has a chip in it. If it says "pay pass" or something similar on the back, or you can "wave" it at a reader, it has a chip in it. The general consensus is that anyone with an RFID reader can swipe your info if they are within a few feet of you, unless you have a "tin foil hat" wallet that can block the signal.
The easiest way to "fix" the problem is with a small hammer and a center punch. Flip the card over and look above the first 4 numbers of your account number and to the right of the short signature strip. As you tilt the card in the light (like you do to see the hologram that's on the front of some cards) you will see a little square, about a quarter inch to a side. That's the chip. Set the punch on it, with the card on a hard surface, and give it a sharp tap (No John Henry swing, just a good rap). You'll shatter the chip inside, and leave the card otherwise undamaged.
The most fun way to do it though is in the microwave. 3 seconds (NO MORE!) on high and the chip is toast. Unfortunately, it most often also ruins the mag stripe, and when the antenna catches fire, it comes through the front of the card. Plus, when the chip explodes, it leaves an unsightly bulge in the card that you have to hammer back flat as well as you can.
We had someone steal our check order form about a year ago (we caught it before anything was taken, but still

) and I am ultra paranoid about that stuff now. Or am I really paranoid if it does happen???
Good luck getting the creep.