Richard Rocco, a toxicologist, notes the accuracy and reliability of gas chromotography, mass spectroscopy as a confirmation test for drug use. He points out the importance of a confirmation test when the less reliable initial test is positive. Arthur McBay, another toxicologist, questions the cost-effectiveness of drug testing and its intrusion into citizens' privacy. Allan Adler, legislative counsel for the American Civil Liberties Union, argues that drug testing by employers should be conducted only when there is probable cause to suspect that a particular person is using drugs in the workplace or is coming to work under the influence of controlled substances. Nanette Everson of the U.S. Justice Department states that Federal courts have upheld drug testing and that it is analogous to an administrative search that does not require probable cause. Adler responds that the courts have upheld drug testing only on the basis of individualized suspicion in most cases.