State and federal authorities follow the movements of thousands of Americans each year by secretly monitoring the location of their cellphones, often with little judicial oversight, in a practice facing legal challenges.

Electronic tracking, used by police to investigate such crimes as drug dealing and murder, has become as routine as “looking for fingerprint evidence or DNA evidence,” said Gregg Rossman, a prosecutor in Broward County, Fla.

The use of cellphone tracking by authorities is among the most common types of electronic surveillance, exceeding wiretaps and the use of GPS tracking, according to a survey of local, state and federal authorities by The Wall Street Journal.

The widening practice also presents one of the biggest privacy questions in a generation: Do police need a search warrant to follow a person’s minute-by-minute movements using satellite or cellphone technology?

The Supreme Court heard arguments Tuesday in the case of Antoine Jones, whose movements were electronically tracked for a month after police attached a global positioning satellite, or GPS, device to his wife’s Jeep Grand Cherokee. A drug conviction against the Washington, D.C., nightclub owner was overturned on appeal because such intrusive monitoring should require a search warrant, the appeals court said.

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