What principle regarding electronic surveillance was established in Katz v. United States?

The principle established in Katz v. United States fundamentally transformed the understanding of privacy rights as they pertain to electronic surveillance. The decision held that the Fourth Amendment protection against unreasonable searches and seizures extends to areas of personal privacy, even when the individual is in a public space. The case centers on the concept of "reasonable expectation of privacy," which dictates that for a warrant to be bypassed, an individual's expectation of privacy must be deemed unreasonable.

In Katz, the Supreme Court determined that individuals have a reasonable expectation of privacy in their conversations, even if they are speaking in a public phone booth. This ruling highlighted that if the government wants to conduct electronic surveillance—such as wiretapping—of conversations where individuals have a reasonable expectation of privacy, a warrant is necessary. Therefore, the requirement for a warrant helps to ensure that such intrusions are justified and lawful, protecting individual privacy rights against unwarranted government interference.

The other choices inadequately reflect the nuances of privacy in the digital age that the Katz ruling emphasized. While it is true that individuals may have diminished expectations of privacy in certain contexts or public settings, the core takeaway from Katz is the necessity of a warrant for those situations where a reasonable expectation of privacy exists. This key takeaway shapes how law