Scenario
Some high-tech scammers working in restaurants, gas stations, and other establishments have small electronic boxes known as "skimmers" hidden near the cash register.
How It Works
Skimmers steal information like name, address, telephone number, credit limit, and PIN encoded on credit cards when the cards are swiped through them. Unlike a conventional credit card scanner, a skimmer is not attached to a phone line or cash register, and typically is concealed out of customers' view. The skimmers are easily concealed and have the appearance of a normal credit/debit card "swipe" equipment.
Self Defense
Try not to let your card out of your sight. Of course, this isn't always possible, but when it is, pay close attention. That alone may make a scammer less likely to try anything. Pay close attention to credit/debit care statements. In most instances your credit/debit information is used without your knowledge that a theft has occurred.