In the case of Chambers v. Maroney, Correctional Superintendent (1969), the U.S Supreme Court ruled that police officers were justified in searching a vehicle without a warrant if they had probable cause to believe it contained evidence of a crime. The court held that given the inherent mobility of vehicles, waiting for a warrant could result in loss of evidence. In this particular case, four men were arrested shortly after an armed robbery and their car was taken to the station where it was thoroughly searched without obtaining a search warrant first. The search led to discovery of incriminating items which were used as evidence against them at trial leading to convictions. On appeal, they argued that these items should have been excluded from trial because they resulted from an unconstitutional search under Fourth Amendment protections against unreasonable searches and seizures but their argument was rejected by both lower courts and ultimately by Supreme Court.

In the dissenting opinion of Chambers v. Maroney, Justice Harlan argued that the majority's decision to allow warrantless searches of automobiles based on probable cause was a dangerous expansion of police powers and an erosion of Fourth Amendment protections against unreasonable searches and seizures. He contended that such broad discretion given to law enforcement could lead to abuses, particularly in situations where there is no immediate threat or danger. Furthermore, he disagreed with the majority's view that searching a vehicle at a later time after it has been moved from the scene would be impractical or inconvenient; instead, he believed this should not override constitutional rights. In his view, unless there are exigent circumstances justifying immediate action without obtaining a warrant first - which were absent in this case - any search conducted should be deemed unconstitutional.