The adoption of drug testing as a strategy of social control can be attributed to the ever-expanding "war" against drugs and to the technological and administrative developments that have made drug testing cheaper, more reliable, and more consistent with norms of privacy. The Federal Government has played a pivotal role in promoting drug testing. Drug testing is most often used in environments, such as the military and the workplace, where the use of drugs may decrease employee productivity or compromise company secrets. It is also used by the criminal justice system to monitor its clients during pretrial release, probation, and parole, as well as in prison. The growth and routinization of drug testing has not gone unchallenged. All public-sector agencies and organizations must adhere to Fourth Amendment limitations on searches and seizures. Drug testing in the private sector also faces obstacles. The National Labor Board has held that implementation of drug testing for employees constitutes a "material change" in the employees' working conditions and is subject to collective bargaining. Drug testing has been challenged on two constitutional grounds: as a due process violation and as an unreasonable search and seizure. Regarding drug testing by government agencies, the U.S. Supreme Court has held that drug testing involves an administrative search that serves regulatory, rather than law enforcement, purposes and is constitutional without a warrant if the government's interest outweighs the intrusion on individual privacy. After almost 20 years, drug testing has become an accepted feature of American society. The costs of drug testing, coupled with evidence of a growing frustration or cynicism regarding the drug "war," raise questions about the future prevalence of drug testing. 44 footnotes