[JURIST] The US Supreme Court [official website] ruled [opinion, PDF] Monday in United States v. Jones [SCOTUSblog backgrounder] that the government’s attachment of a global positioning system (GPS) [JURIST news archive] device to a vehicle, and its use of that device to monitor the vehicle’s movements, constitutes a search under the Fourth Amendment [text]. The federal government sought Supreme Court review after the US Court of Appeals for the District of Columbia Circuit ruled [JURIST reports] in 2010 that prolonged use of GPS to monitor suspects’ vehicles violates the Fourth Amendment protection against unreasonable searches and seizures. Affirming the decision below, Justice Antonin Scalia delivered the opinion of the court, which was joined by Chief Justice John Roberts and Justices Anthony Kennedy, Clarence Thomas and Sonia Sotomayor:

It is important to be clear about what occurred in this case: The Government physically occupied private property for the purpose of obtaining information. We have no doubt that such a physical intrusion would have been considered a “search” within the meaning of the Fourth Amendment when it was adopted.

Sotomayor also filed a concurring opinion. Justice Samuel Alito filed a concurring opinion, joined by Justices Ruth Bader Ginsburg, Stephen Breyer and Elena Kagan. Alito “would analyze the question presented in this case by asking whether respondent’s reasonable expectations of privacy were violated by the long-term monitoring of the movements of the vehicle he drove.”

The court heard arguments [JURIST report] in the case in November. The government argued that under US v. Knotts [opinion text], a GPS tracker is as permissible as monitoring a car by using a beeper inside the car for tracking purposes. Respondent’s attorney argued that placing the GPS in the car created a seizure of the vehicle. JURIST Guest Columnist Jim Harper [professional profile], Director of Information Policy Studies at the Cato Institute, argued in a piece for JURIST that the Supreme Court should use US v. Jones as an opportunity to reaffirm Fourth Amendment protections against unreasonable search and seizure, particularly in light of technological advances.