The U.S. Supreme Court case National Treasury Employees Union et al. v. Von Raab, Commissioner, United States Customs Service (1988) involved a challenge to the U.S. Custom Service's drug testing program for employees seeking promotions or transfers to certain positions involving direct drug interdiction or requiring carrying of firearms. The National Treasury Employees Union and several individual plaintiffs argued that this policy violated their Fourth Amendment rights against unreasonable searches and seizures. In its decision, the Supreme Court upheld most aspects of the Customs Service's drug testing program as constitutional under the Fourth Amendment by a 5-4 majority vote. The court ruled that while urine tests do constitute a "search" within meaning of Fourth Amendment, government interests can sometimes override privacy concerns in such circumstances where public safety is at stake. However, it also held that if there was no reasonable suspicion of employee drug use then mandatory testing would be an unreasonable invasion of personal privacy unless there were special needs beyond normal law enforcement requirements justifying it.

In the dissenting opinion for National Treasury Employees Union et al. v. Von Raab, Justice Scalia argued that the majority's decision to uphold drug testing of U.S. Customs Service employees without a warrant or individualized suspicion was in violation of the Fourth Amendment's protection against unreasonable searches and seizures. He contended that this ruling expanded governmental power at the expense of citizens' constitutional rights, setting a dangerous precedent for future cases involving civil liberties. Furthermore, he criticized the majority's reasoning as inconsistent and flawed because it failed to establish clear standards for when such invasive procedures could be justified by public safety concerns or other compelling interests.