In Johnson v. United States, the Supreme Court ruled on a case involving illegal search and seizure. The police had entered a hotel room without a warrant due to an anonymous tip about opium use, which they claimed gave them probable cause for immediate action. They arrested Ms. Johnson after finding drugs in her possession during their search of the premises. However, the court held that this was not sufficient grounds for bypassing Fourth Amendment protections against unreasonable searches and seizures - even if it meant allowing some crimes to go unpunished as a result. The majority opinion stated that no amount of probable cause could justify such intrusions absent exigent circumstances; otherwise, law enforcement officers would be able to force entry into any home at will by merely stating they have reason to believe criminal activity is taking place therein. This decision reinforced individuals' rights under the Fourth Amendment and set important precedents regarding what constitutes "exigent circumstances" (i.e., situations where obtaining a warrant is impractical or dangerous) justifying warrantless searches.

In the dissenting opinion for Johnson v. United States, Justice Frankfurter argued that the majority's decision undermined Fourth Amendment protections against unreasonable searches and seizures. He contended that allowing law enforcement to enter a private residence without a warrant based on an officer's subjective belief of criminal activity set a dangerous precedent. Frankfurter emphasized that constitutional rights should not be sacrificed for expediency or convenience in law enforcement practices. The justice also expressed concern about potential abuses of power by police officers who might exploit this ruling to justify unwarranted intrusions into citizens' homes under the guise of probable cause. In his view, such actions would erode public trust in law enforcement institutions and undermine civil liberties.