GPS Tracking Is a ‘Search’

CDT today joined in a “friend of the court” brieffiled at the U.S. Supreme Court in what could be one of the major Fourth Amendment cases of the decade, U.S. v. Jones, which poses the question of whether the police can plant a GPS device on a person’s car for 24/7 tracking without judicial oversight.

The brief says:

The issue before the Court in this case is not whether GPS tracking ever may be used by the government. Rather, it is whether the government must obtain a warrant in order to employ this technology.

CDT’s brief was filed jointly with our frequent partner in Fourth Amendment cases, the Electronic Frontier Foundation.  Several things make the brief special.  First, it is also signed by four technologists, whose expertise lends special credibility to the brief.  Moreover, one of the four is Roger Easton, often called the father of GPS for his groundbreaking work at the Naval Research Laboratory.  The other three represent the current generation of experts on networking, mobility and security: Andrew Blumberg of the University of Texas, Norman Sadeh of Carnegie Mellon, and Matt Blaze (who broke the Clipper chip) of the University of Pennsylvania.

The brief was written by Andy Pincus, a former Assistant to the Solicitor General of the United States and one of the leading Supreme Court advocates today.

True to CDT’s approach to tech policy issues, half of the brief focuses on the technology of GPS, half on showing how that technology interfaces with legal precedent.  Our main point is that GPS technology is fundamentally different from the “bumper beepers” whose use the Supreme Court ruled in 1983 was not covered by the Constitution’s search and seizure clause.  GPS, in contrast, is so different from human observation and generates such precise and pervasive data that it violates the average person’s reasonable expectation of privacy, even on the public streets.

For example, the brief notes that:

As receivers shrink in size, it will be possible to install them in a person’s clothing… the government would be able to use the technology to track the movements of large numbers of individuals even more directly and precisely than through the attachment of a GPS receiver to a vehicle.

Oral argument in the case is scheduled for November 8.  The Court may not rule on the case until next year.