An eagle - eyed member of public spotted that a skimming device had been fitted to a cash machine outside NatWest Bank on Chiswick High Road . The scam , known as the ' Lebanese Loop ' involves fitting a false cover over the card slot . Police said the man noticed the device when the machine would not return his card . Police were called to the scene and removed the device . The ' Lebanese Loop ' is a common scam where which a false cover is fitted over the card slot with a camera looking down onto the keypad . ;