INS v. Delgado

Acting on valid warrants, INS agents conducted searches of two garment factories seeking undocumented workers, stationing themselves near exits and questioning employees at their workstations about citizenship while allowing other employees to keep working and move freely around the factory. Delgado and several coworkers, along with their union representative (collectively Plaintiffs), sued the INS claiming the searches violated their Fourth Amendment rights; the district court dismissed the union for lack of standing and ruled for the INS, finding no one had been detained, but the court of appeals reversed, holding the entire workforce had effectively been seized because agents stationed at the exits would lead a reasonable worker to believe he couldn't leave. The Supreme Court granted certiorari.