In the 1970 Supreme Court case United States v. White, the issue of Fourth Amendment rights regarding unreasonable searches and seizures was addressed. The defendant, James A. White, had been convicted on illegal gambling charges based on evidence obtained through a hidden microphone worn by an informant during their conversations. White argued that this constituted an unlawful search under the Fourth Amendment as there was no warrant for such surveillance. The Supreme Court disagreed with his argument in a 5-4 decision stating that one assumes the risk when speaking to another person that they could be giving information to police or recording their conversation; therefore it does not violate any reasonable expectation of privacy protected by the Fourth Amendment. This ruling expanded upon previous decisions allowing warrantless wiretaps in cases where national security is at stake (Olmstead v U.S., 1928) and reaffirmed its stance from Katz v U.S.,1967 which stated that what someone knowingly exposes to public view is not subject to Fourth Amendment protection.

In the dissenting opinion for United States v. White, Justice Harlan argued that the majority's decision to allow warrantless electronic surveillance violated an individual's reasonable expectation of privacy under the Fourth Amendment. He contended that this ruling expanded government power and threatened civil liberties by permitting law enforcement to use technology in ways not envisioned when the Constitution was written. Furthermore, he disagreed with the majority’s reliance on Hoffa v. United States and Lewis v. United States as precedents because those cases involved physical intrusion rather than electronic eavesdropping which is more invasive and pervasive in nature. In his view, a person should have a protected right to private conversation regardless of whether they misjudged their confidant’s trustworthiness or not.