> A very cheap and simple solution would be to set up a small CMOS camera with an infrared filter attached. With a lens properly focussed on the relevant areas (keypad, card reader etc), a “key” image of the ATM can be aquired in this spectrum. By feeding the images to software, an alogarithm can be designed to detect when the ATM is not in use. This would allow for an unimpeded image of the ATM, which can then be compared with the original “key” image. Any alterations in shape, size or IR reflectivity can be detected and an alert sent.