The Supreme Court said Monday that law enforcement authorities might need a probable-cause warrant from a judge to affix a GPS device to a vehicle and monitor its every move — but the justices did not say that a warrant was needed in all cases.
The convoluted decision (.pdf) in what is arguably the biggest Fourth Amendment case in the computer age, rejected the Obama administration’s position that attaching a GPS device to a vehicle was not a search. The government had told the high court that it could even affix GPS devices on the vehicles of all members of the Supreme Court, without a warrant.
“We hold that the government’s installation of a GPS device on a target’s vehicle, and its use of that device to monitor the vehicle’s movements, constitutes a ‘search,’” Justice Antonin Scalia wrote for the five-justice majority. The majority declined to say whether that search was unreasonable and required a warrant.
All nine justices, however, agreed to toss out the life sentence of a District of Columbia drug dealer who was the subject of a warrantless, 28-day surveillance via GPS.
Four justices in a minority opinion said that the prolonged GPS surveillance in this case amounted to a search needing a warrant. But the minority opinion was silent on whether GPS monitoring for shorter periods would require one.
Justice Sonia Sotomayor voted with the majority, but wrote in a separate, solo opinion that both the majority and minority opinions were valid. She also suggested that Americans have more rights to privacy in data held by phone and internet companies than the Supreme Court has held in the past.
“I think it’s fair to say, the use of a a GPS device like this requires a warrant where they are tracking him for a long time,” Thomas Goldstein, who has argued dozens of cases before the Supreme Court, said in a telephone interview.
The Justice Department maintained it had probable cause in the case, though not a valid warrant. The majority said because of procedural rules, it would not decide whether the “search” in this case required a warrant. “We consider that argument forfeited,” the majority wrote.