[lelio]

Not really an ATM hack, but there was a case in NYC where the cashier would swipe your card on the store's credit card machine, and then again on their local card reader. When you entered your PIN on the keypad someone was watching to get the 4 digits.
I think the plan was to clone your card and then use it. I can't see how this system would fail as its my understanding that nothing's written to your card when you swipe it through a machine. If there was you could easily detect this as the 2nd card wouldn't know the 2nd bit turned from "AD" to "BC" or something similiar.

[Southack]

"I can't see how this system would fail..."

Well, there's always that pesky camera taking digital pictures of every ATM use/attempt!