Computers are now being used in most human activities. For example, in police work computers have been programmed to match fingerprints and this application identified a serial killer in California. Before this program, the labor costs were simply too high to match fingerprints unless there were suspects. A hot area of computation in the arts is music synthesizers. In sports computers are used to analyze athletes' performances. In medicine, a computer program has been developed which stimulate nerves to allow paraplegics to move their muscles. One success story is a young lady paralyzed from waist down who was programmed to ride a bicycle and walk.