The Supreme Court ruled unanimously on Monday that law enforcement authorities violated the Constitution when they placed a GPS tracking device on a suspect’s car and surveyed its movements for 28 days. The police must get a search warrant before using this type of technology to track criminal suspects, according to the decision.
The justices divided 5-to-4 on the rationale for the decision; however, the majority said that the problem was the placement of the device on private property. That ruling avoided questions such as how to treat information gathered from devices installed by the manufacturer and how to treat data held by third parties like cellphone companies.
Though the ruling was limited to physical intrusions, the opinions in the case collectively suggested that a majority of the justices are prepared to apply broad Fourth Amendment privacy principles unrelated to such intrusions to an array of modern technologies, including video surveillance in public places, automatic toll collection systems on highways, devices that allow motorists to signal for roadside assistance and records kept by online merchants.