March 12th, 2015

The Mosaic Theory, Riley, and the Legacy of Jones

USA v. Timothy Carpenter (Amicus Brief), Brennan Center for Justice,

“EFF Fights Government’s Effort to Get Cell Location Records Without a Warrant,” Electronic Frontier Foundation,”

“The Mosaic Theory of the Fourth Amendment,” Orin S. Kerr,

By: David G. Krone

In U.S. v. Jones, five U.S. Supreme Court justices signed or joined concurring opinions indicating they would support a “mosaic theory” of the Fourth Amendment whereby the aggregation of locational information would have amounted to a search. As Justice Alito wrote, “relatively short-term monitoring of a person’s movements on public streets accords with expectations of privacy that our society has recognized as reasonable. But the use of longer term GPS monitoring in investigations of most offenses impinges on expectations of privacy.” In that case, the Supreme Court ultimately ruled in favor of the appellant based on a theory of physical trespass on the appellant’s car. Since that case, organizations such as the Brennan Center for Justice at NYU the Electronic Frontier Foundation (EFF) and the American Civil Liberties Union (ACLU) have pushed courts to recognize the privacy Interest in cell tower through amicus briefs filed in cases involving convictions based on the data. In particular, they have cited the Supreme Court’s ruling in California v. Riley, relating the privacy interest that the Court found in the type and quantity of data on a cell phone to the interest a defendant would have in cell tower data that is just as potentially invasive.

Most recently, an amicus brief signed by all three organizations the specifically addresses USA v. Timothy Carpenter in the 6th Circuit. In Carpenter, the defendant is appealing his conviction of robbery charges based of evidence that “included five months of cell site data procured without a warrant.” The amicae argue, firstly, that, much like the GPS surveillance information in Jones, the cell site location information (CSLI) acquires reveals invasive and precise information about the defendant’s locations. The amicae note that, during that five month period, the CSLI records the defendant’s location at the beginning and end of each phone call—revealing, in addition to his proximity to the robbery, when he was at church, at home and when he slept away from home. Secondly, the amicus brief argues that the CSLI record was a Fourth Amendment search requiring a warrant by citing both the Alito and Sotomayor concurrences in Jones, as well as the Court’s assessment of the of cell phone data in Riley. As the brief states, “The expectation that a cell phone will not be tracked is even more acute than is the expectation that cars will not be tracked because individuals are in their cars for discrete (and typically brief) periods of time, but carry their cell phones with them wherever they go.” In fact there is potentially greater privacy interest in the here than in in Jones because, because CSLI may include information recorded while in the defendant’s home. Finally, the brief also argues that the third-party doctrine (as articulated in Smith v. Maryland) should not apply, because people, “do not input or knowingly input their location information to their wireless carrier” (emphasis added).

The 6th Circuit has yet to hear oral arguments in USA v. Carpenter. However, other circuits have remained conflicted. In 2013, the EFF and the ACLU submitted an amicus brief in the 11th Circuit case, United States v. Davis, similarly basing their argument on the quantitative and qualitative differences in CSLI. In June 2014, the Court sided with the amicae, but later elected to rehear the case en banc, seeking further arguments on whether the CSLI acquisition violated the Fourth Amendment. Courts do face considerable concerns in adopting a “mosaic theory” approach to Fourth Amendment searches. As Georgetown Washington Law Professor Orin Kerr points out in his seminal article on “The Mosaic Theory of the Fourth Amendment,” adopting this approach would require future courts to tackle issues in applying the standard. For instance, Courts would have to determine what standard should apply and whether data collection alone would meet the threshold, or whether post-collection analysis or use would also be required. The Courts would also have to decide the scope of the mosaic theory not only in terms of duration and scale but which surveillance methods count. Finally, the Courts will also have to address issues of constitutional reasonableness and whether remedies such as the exclusionary rule will apply.

Nevertheless, as Kerr himself notes, Courts are accustomed to dealing with ambiguity in defining Fourth Amendment protections. The Supreme Court has consistently recognized in cases ranging from Kyllo to Riley the need to shape the law in anticipation of the persistent march of technology. For better or for worse, the bulk, machine-readable data is gaining an increasingly prominent role in society, from our cell phones to Facebook. As Justice Roberts colorfully pointed out in the unanimous Riley opinion, comparing cell phone data to the evidence found in a physical object like a wallet, “is like saying a ride on horseback is materially indistinguishable from a flight to the moon. Both are ways of getting from point A to point B, but little else justifies lumping them together.”