In Skinner v. Railway Labor Executives' Ass'n, 489 U.S. 602 (1989), the railroads had a special need, in order to prevent drug or alcohol-related accidents, to ban workers' use of alcohol or drugs and to test their blood or urine to assure the ban's effectiveness. 489 U.S. at 620-21. Because the authorizing regulations identified the circumstances justifying the testing and the conditions under which it occurred, "there were virtually no facts for a neutral magistrate to evaluate." Id. at 622. More importantly, when delay to seek a warrant would seriously impede the collection of critical evidence, the balance tipped in favor of finding a warrantless intrusion reasonable. Id. at 623-24. The testing in Skinner was not random, but it was also not based on individualized suspicion. Id. at 624. The Court nevertheless concluded that by working in a highly regulated industry, the employees had diminished expectations of privacy, id. at 627, and that the interest in testing was "compelling," in part because of the difficulty in detecting in any other way employees who were impaired while at work. Id. at 628-29.