In the case of Lee et al. v. Florida, 1967, the U.S. Supreme Court ruled that evidence obtained by wiretapping was inadmissible in state courts because it violated the Fourth Amendment's protection against unreasonable searches and seizures. The decision extended a previous ruling which had only applied to federal cases (Katz v United States). In this particular case, Miami police used a warrantless wiretap to gather evidence on illegal gambling operations run by Robert Earl Lee and Ernest Eugene Kirksey. The defendants were convicted based on this evidence but appealed their convictions all the way up to the Supreme Court arguing that their constitutional rights had been violated due to unlawful search and seizure of private communications without proper warrants or consent.

In the dissenting opinion for Lee et al. v. Florida, Justice Harlan argued that the majority's decision to exclude evidence obtained through wiretapping was a misinterpretation of Congress' intent in passing Section 605 of the Federal Communications Act. He contended that this section was not meant to protect privacy rights but rather aimed at preventing unauthorized persons from intercepting and divulging communications, thereby protecting property interests in communication services. Furthermore, he believed that there should be no constitutional barrier against states using intercepted messages as evidence if they were legally obtained under state law and did not involve federal officers or violate federal law. The dissent also criticized the majority's reliance on previous court decisions which had interpreted Section 605 differently than intended by Congress.