What does the Katz formula indicate?

The Katz formula is a legal principle derived from the Supreme Court case Katz v. United States, which established the standard for determining when a government action constitutes a search under the Fourth Amendment. The correct interpretation of the Katz formula is that government intrusion, when it occurs in a context where an individual has a reasonable expectation of privacy, constitutes a search that requires a warrant or probable cause.

This means that if a person has a subjective expectation of privacy that society recognizes as reasonable, then any government action that infringes upon that expectation qualifies as a search. This principle seeks to protect individuals against arbitrary governmental intrusions in situations where privacy should be afforded. In contrast, the other options lack this foundational legal context or misrepresent the scope of privacy and government involvement, making them incorrect in the context of the Katz formula.