ATM skimming is like identity theft for debit cards and it comes in two major forms, ancient and modern. The ancient (as in a few years ago) occurs when thieves use hidden electronics to steal the personal information stored on your card and record your PIN number. That’s why skimming takes two separate components to work. The first part is the skimmer itself, a card reader placed over the ATM’s real card slot. When you slide your card into the ATM, you’re unwittingly sliding it through the counterfeit reader, which scans and stores all the information on the magnetic strip.

However, to gain full access to your bank account on an ATM, the thieves still need your PIN number. That’s where cameras come in — hidden on or near the ATMs, tiny spy cameras are positioned to get a clear view of the keypad and record all the ATM’s PIN action . Always pay attention to objects mounted on the ATM or located close by. A pinhole or off-color piece of plastic could give away the camera’s hiding place. Cameras could even be hidden in brochure racks.

That is the relatively crude, earliest form of automated ATM skimming. Now, criminal rings have gotten more sophisticated: they have create a simple, tiny chip that can be appended to the ATM motherboard — inside the machine — that logs all card names, numbers and PIN numbers. Then, it encrypts the data. Then, this chip has a small bluetooth transceiver that allows someone walking by the ATM to connect to the skimming chip via bluetooth and download all of the card data. Eastern European crime rings are doing this all over Europe and Mexico. They target large hotels in expensive travel destinations, usually bribing an ATM technician for access to the inside of the ATM, to install the chip.