Police use of GPS surveillance and society’s expectations of privacy clashed in the U.S. Supreme Court on Tuesday as justices weighed new technology and its impact on Fourth Amendment rights.

With multiple references to the novel “1984,” a majority of the justices seemed uncomfortable with the federal government’s defense of law enforcement’s warrantless use of a GPS tracking device on a suspected drug dealer’s car over a four-week period. But the justices also struggled to find a legal way to regulate that type of surveillance.