Advances in Attacking ATMs Cash traps and card traps are the new thing:
[Card traps] involve devices that fit over the card acceptance slot and include a razor-edged spring trap that prevents the customer’s card from being ejected from the ATM when the transaction is completed.
"Spring traps are still being widely used," EAST wrote in its most recently European Fraud Update. "Once the card has been inserted, these prevent the card being returned to the customer and also stop the ATM from retracting it. According to reports from one country despite warning messages that appear on the ATM screen or are displayed on the ATM fascia customers are still not reporting when their cards are captured, leading to substantial losses from ATM or point-of-sale transactions."
More descriptions, and photos of the devices, in the article.