mgrant@MIMSY.UMD.EDU (Michael Grant) (12/24/86)
I have seen one of these cards. The card is the size of a credit card, made of thin metal. A number like 5, 10, 20 units is printed on the front. Also, on the front in a band that is placed about where the magnetic strip on a credit card is, if you look closly, you can see tiny squares protruding from the surface, one square for each unit that the card is worth. The hack is probebly something like scratching one of these squares. They do not appear to be holograms. They remind me of the same sort of material that is used in book stores to stop book theft. -Mike