This case started from the premise of citizens having “having reasonable expectation of privacy”. The FBI felt that placing a listening device outside of a public phone booth did not violate Katz privacy because it did not penetrate the wall. Whether or not the phone calls were to be considered a search depended upon whether or not Katz had “reasonable expectation that his calls were private. The court stated that what a person knowingly exposes to the public even in his home or office is not subject to Fourth Amendment protection.
FACTS:
Katz was a bookie who used a telephone booth to transmit illegal gaming bets from Los Angeles, Miami and Boston. The FBI placed a device on top of the phone booth to monitor all of his conversations