In 1964, ADT was found to be a monopoly in restraint of trade. It was shown to provide almost 80% of the central station alarm service in the United States. In some cities, such as New York City and Memphis, Tennessee, they were the sole provider. They were also found to have forced competitors out of business by lowering prices below cost. They would charge national accounts very low prices in cities with competitors and much higher prices where no competition was available. ADT was forced to adopt a national price list, which could not be varied, to help establish central station competitors in cities without competition, and to pay fines and triple damages to the federal government, customers, and local competitors.