To accomplish this task, the thief places an electronic "skimmer" -- a card swipe device that reads the information on the card's magnetic strip -- on the ATM machine. Attached to the device, or placed discreetly elsewhere, is a small camera that captures the customer's PIN number when they enter it. The information is either collected by the device, or transmitted to a remote receiver. The thief then takes the codes and creates a counterfeit ATM card in order to empty the victim's bank account. Some skimmers can even capture the information and send it to the ATM at the same time. Since the machine works normally, the victim is unaware that they have just given a thief the key to their account.
To be safe, look at the ATM and make sure the card reader is flush with the rest of the ATM.
