Card Skimmers: What They Are and How to Protect Yourself
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A card skimmer is a device used to capture information from a credit, debit or ATM card by reading the card's magnetic strip. Identity thieves and other scammers use that information to gain access to the victim's credit line or bank account.
Credit-card fraud can happen at restaurants or bars, where servers take cards away from customers to swipe them. Unscrupulous employees will take this opportunity to swipe the cards twice, once in the establishment's legitimate card reader, the second time in a skimmer that the server keeps on his or her person.
The skimmer will capture the card number and the user's full name, and the server can write down the card's three- or four-digit security code. If the lighting is low, all this can happen only several feet away from the unsuspecting customer.
In retail establishments, skimmers are often handled by cashiers in the pay of criminals. There also have been instances of bogus card readers, complete with PIN pads, being placed in stores without the knowledge of employees.
Card skimming also happens at automated teller machines. Enterprising identity thieves may install a skimming device on the face of the ATM itself; when customers insert their cards, the cards pass through the skimmer first.
The skimmer can't capture PIN information, but some criminals get around this problem by hiding a small but powerful video camera on or near the ATM. The cameras record each PIN entered and time-stamp the recording to match the PINs with card usage.
More sophisticated criminals instead attach a phony keypad over the legitimate one. Customers enter their identification number as instructed to do so by the ATM, not realizing they're also entering this data into a device designed to steal it.
Panic at the gas pump
Skimmers also can be found attached to gas-station credit-card readers on self-service pumps.
Customers stopping for fill-ups generally don't expect to encounter fraudulent credit-card devices on the pumps, so they insert their cards without carefully inspecting the card reader. If the gas station isn't brightly lit, it's even easier for skimming devices to remain undetected.
Fraudulent skimming devices on gas pumps can look so realistic that it's almost impossible for someone to notice without extensive personal experience investigating credit-card fraud.
This type of theft isn't limited to rural, back-road gas stations; "carders" often target huge gas stations on major interstate highways because of the tremendous volume of traffic that passes through.
High-tech, long distance
Traditionally, card-skimming devices store data on a memory card or chip in the device itself, which means that criminals who place skimmers on point-of-sale devices or ATMs have to regularly visit the devices to retrieve the information, and servers who carry skimmers have to download the data after hours.
More recently, thieves have begun using advanced skimmers that transmit scanned data over a cellular network or via Bluetooth.
Bluetooth devices have a very short range, about 30 feet, but it's far enough for a criminal in a parked car with a laptop to pick up. Cellular skimmers, however, can easily send data hundreds of miles away.
Protection and prevention
To protect themselves from card skimmers at ATMs, gas pumps or retail stores, cardholders should carefully examine all card-reading devices before use.
If anything seems out of order, the customer should choose another ATM or gas pump, or postpone the transaction entirely.
Don't use ATMs that sit outside on city sidewalks, with wires leading back into dimly lit shops. You don't know who's going to be getting your card information.
In a bar or restaurant, keep an eye on what the waiter or cashier does with the card. If you're not familiar with the place, pay in cash.
Whenever possible, it's best to process a transaction as "credit" rather than "debit," as this eliminates the need to enter the card's PIN and thus robs a criminal of vital information.
All these precautions may result in a bit of inconvenience, but that pales in comparison with the hassle of identifying and rectifying fraudulent charges.