The New York City Transit Authority (defendant) promulgated a policy that it would not hire or employ persons currently participating in one of New York City’s several methadone maintenance programs. About 40,000 persons received methadone treatments in New York, and treatments were primarily administered to treat the physical withdrawal symptoms of heroin addicts. Beazer (plaintiff) and three other persons brought suit in federal district court against the New York City Transit Authority in a class action on behalf of all persons who had been, or would in the future be, subject to discharge or rejection as employees of the Transit Authority because they participated in a methadone maintenance program. The district court ruled in favor of Beazer and found the employment policy unconstitutional. The decision was affirmed by the Court of Appeals for the Second Circuit, and the United States Supreme Court granted certiorari.