Skimmers have been growing ever more advanced in recent years. Do you think you'd be observant enough to notice that this checkout front-plate was about to gobble up your card details? Krebs on Security has obtained these images of a card skimmer used on a self-checkout terminal at a Safeway store in Maryland. (Safeway recently admitted that it was investigating card skimming attacks at several of its stores.)
The device is what's known as an overlay skimmer: It slips straight over the top of a pay point in order to grab data from your card's magnetic stripe and capture your PIN, while requiring no direct hardware interaction with the checkout itself. Because it doesn't interfere with your payment, the only thing it needs to do is look convincing -- which it does.
Of course, chip-and-pin skirts this issue altogether. But if you find yourself at a checkout which requires you to swipe your card, you may want to give the fascia a quick check (without, you know, destroying the pay point altogether). And as ever, if you're in the slightest suspicious about where you're putting your card, you should walk away without making the purchase.