The Supreme Court issued a landmark decision Monday regarding warantless surveillance that could have vast implications for privacy and technology in the years to come. In a unanimous ruling, the justices said the police violated the Constitution when they placed a GPS device on the underside of a suspect’s car and used the device to track and record his movements for a month. The court, however, was closely divided on its reasoning for the decision, and the split could leave several important privacy-related questions unresolved.
The question in the case was whether Washington, D.C. police violated the Fourth Amendment rights of the defendant, Antoine Jones, when they placed a GPS tracking device on his car to gather evidence for a potential drug trafficking case. The government argued that Jones had no “reasonable expectation of privacy” in either the location of the device — the underside of his car — or in the places where he drove the car, such as public roads. The police failed to obtain a warrant before attaching the device to Jones’s car.
All nine of the justices agreed that the action was unconstitutional, but split 5-4 on why. Writing for the majority, Justice Antonin Scalia offered a narrow justification for the ruling, citing the Fourth Amendment’s guarantee that the “right of the people to be secure in their persons, houses, papers and effects, against unreasonable searches and seizures, shall not be violated.” A vehicle, Scalia wrote, counts as an “effect,” and physically placing a GPS device on a person’s car counts as an “unreasonable search.” Once the court determined that a physical trespass had occurred, Scalia wrote, there was no need to go any further:
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.
This reasoning, however, leaves unanswered the broader and arguably more important question of whether the government’s use of technologies that don’t involve physical trespassing — cell phone location tracking, for example — violates the Constitution. What if, instead of attaching a GPS device to your car, the police decide to intercept the digital information that streams from your iPhone to cell towers every time you use Yelp to find nearby restaurants or search for directions on Google Maps?
This ruling, according to the majority, leaves that question unresolved. In concurring opinions, the four remaining justices argued that the court should have used this case as an opportunity to answer the bigger, privacy-related questions now. Those justices said they would have used a different and more far-reaching standard than the physical trespass analysis used by Scalia.
That standard, Justice Sonia Sotomayor wrote in a concurring opinion, is irrelevant to many modern forms of surveillance which don’t involve physical intrusion. Auto manufacturers can install tracking devices in cars right there in the factory. Smartphones come equipped with location-tracking GPS technology. These devices can reveal a wealth of data about a person’s relationships, political and religious affiliations and so forth, without requiring any physical intrusion on a person’s private property. But they may still violate a person’s reasonable expectation of privacy, Sotomayor wrote:
Awareness that the Government may be watching chills associational and expressive freedoms. And the Government’s unrestrained power to assemble data that reveal private aspects of identity is susceptible to abuse. The net result is that GPS monitoring — by making available at a relatively low cost such a substantial quantum of intimate information about any person whom the Government, in its unfettered discretion, chooses to track — may “alter the relationship between citizen and government in a way that is inimical to democratic society.”
Sotomayor also challenged another long-held tenet of Fourth Amendment jurisprudence: that a person has no reasonable expectation of privacy on information that he or she voluntarily offers to a third party. In the era of Twitter and Facebook, of course, basic, everyday tasks require you to divulge some amount of private information about yourself to a third party. The third-party doctrine then, Sotomayor wrote, may be dangerously out of date.
“This approach is ill-suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks,” Sotomayor wrote. “I for one doubt that people would accept without complaint the warrantless disclosure to the Government of a list of every Web site they had visited in the last week, or month, or year.”
Although Sotomayor’s view was ultimately superseded by the majority, civil liberties advocates nonetheless hailed the opinion as an important moment for privacy rights in the digital age, and a sign that the justices are paying close attention to the bigger, knottier privacy questions posed by developments in digital technology. Catherine Crump, a staff attorney at the American Civil Liberties Union, said in an interview that the Sotomayor opinion was a hopeful sign that “the court is going to make sure that, as technology advances, our privacy rights aren’t left behind.”