In the case of Johnston et al. v. United States (1955), the Supreme Court ruled on whether or not a search warrant was necessary for law enforcement to enter and search a private residence when they had reasonable cause to believe that evidence of illegal activity would be found there. The appellants, Mr. and Mrs. Johnston, were convicted in federal court for conspiracy to violate internal revenue laws related to distilling alcohol without paying taxes on it after officers entered their home without a warrant but with probable cause and discovered an illicit still operation inside. The Johnstons appealed their conviction arguing that the entry into their home violated Fourth Amendment protections against unreasonable searches and seizures because no warrant had been obtained prior to entry by law enforcement officials. However, the Supreme Court upheld their convictions ruling that under exigent circumstances - where delay could result in loss or destruction of evidence - police may enter premises without first obtaining a search warrant if they have probable cause.

In the dissenting opinion for Johnston et al. v. United States, Justice Frankfurter disagreed with the majority's decision to uphold a conviction based on evidence obtained through warrantless wiretapping. He argued that such practices violated Fourth Amendment protections against unreasonable searches and seizures, as well as Fifth Amendment rights against self-incrimination. The justice contended that allowing law enforcement to use illegally obtained evidence would encourage them to disregard constitutional safeguards in their investigations, undermining citizens' privacy rights and eroding public trust in the legal system. Furthermore, he believed this ruling contradicted previous court decisions which had established a clear precedent of excluding unlawfully seized evidence from trials.