Actually reported to me by a friend who says it actually happened to him. In London. a week ago,
Goes to standard ATM.outside branch of own bank Does the usual. Card never appears at the 'take your card' phase. Neither does money. ATM then blinks and says 'out of order'.
Thinking its jammed, and the card will be returned, thinks no more of it. Till come Monday, bank account emptied. Police say 'ah yes, we know that one. It works like this'.
Crims have special spring clip that stops card being ejected. This is simply pushed into place through the card slot.
Crims have own surveillance camera mounted up high across the street, or man in bedsits with video cam or binoculars..
Crims watch to see when card is used, wait till bemused customer wanders off, use special tool to retrieve card.
Crims review video surveillance to ID PIN.
Crims use card till its exhausted.
Moral: If card is eaten by ATM put a block on it immediately. If possible and bank its attached to is open, alert bank.