It’s not news to CoOp readers that Fourth Amendment law is in a state of confusion over how to deal with ever-expanding capacities of state agents to collect information about our movements and activities using a range of surveillance technologies. My colleague David Gray and I have spent lots of time thinking and writing about the fog surrounding this issue in light of United States v. Jones. So we write this post together — Professor David Gray is my brilliant colleague who has been a guest for us in the past. So here is what is on our minds:
The Supreme Court avoided a four-square engagement with these issues last term in Jones by rehabilitating a long-forgotten, but not lost, property-based test of Fourth Amendment search. For most of us, however, the real action in the opinion was in the concurrences, which make clear that five justices are ready to hold that we may have a reasonable expectation of privacy in massive aggregates of data, even if not that is not true for the constituent parts. The focus of the academic debate after Jones, including a really fascinating session at the Privacy Law Scholars Conference in June, has largely focused on the pros and cons of the “mosaic” theory, which would assess Fourth Amendment interests in quantitative privacy on a case-by-case basis by asking whether law enforcement had gathered too much information on their subject in the course of their investigation. Justice Alito, writing for himself and three others, appeared to endorse the mosaic theory in Jones, and therefore would have held that law enforcement engaged in a Fourth Amendment search by using a GPS-enabled tracking device to monitor Jones’s movements over public streets for 28 days, generating over 2,000 pages of data along the way.
Before the ink was dry in Jones, Orin Kerr was out with a powerful critique. Orin’s concerns, which Justice Scalia seems to share, are doctrinal and practical. Christopher Slobogin has since offered a very thoughtful defense of the mosaic theory, which comes complete with a model statute complete with commentary (take notice Chief Justice Roberts!). Professor Gray and I just posted an article on SSRN arguing that, by focusing on the mosaic theory, much of the conversation about technology and the Fourth Amendment has gone badly wrong after Jones. The Sixth Circuit’s opinion in United States v. Skinner confirms the worst of our concerns. Another nod to Orin Kerr for putting a spotlight on this decision over at the Volokh Conspiracy.
The question put to the court in Skinner was whether the “use of the GPS location information emitted from [Skinner’s] cell phone was a warrantless search that violated the Fourth Amendment . . . .” Writing for himself and Judge Clay, Judge Rogers held that “Skinner did not have a reasonable expectation of privacy in the data emanating from his cell phone that showed its location” in the same way that “the driver of a getaway car has no expectation of privacy in the particular combination of colors of his car’s paint.” Because the officers tracking Skinner only did so for three days, Judge Rogers also saw no quantitative privacy interest at stake.
Skinner is confusing in many ways. The court is not entirely clear on what tracking technology was used, how it was used, which line of Fourth Amendment doctrine it relied upon, or how its holding can be reconciled with Kyllo. For now, let’s bypass those issues to focus on what we take to be a dangerous implication of Skinner and perhaps the mosaic theory as well. According to Judge Rogers, none of us has “a reasonable expectation of privacy in the inherent external locatability of a tool that he or she bought.” That is, there is absolutely no Fourth Amendment prohibition on law enforcement’s using the GPS devices installed in our phone, cars, and computers, or trilateration between cellular towers to track any of us at anytime. Because there are no real practical limitations on the scope of surveillance that these technologies can achieve, Judge Rogers’s holding licenses law enforcement to track us all of the time. The mosaic theory might step in if the government tracks any one of us for too long, but it preserves the possibility that, at any given time, any of us or all of us may be subject to close government surveillance.
We think that something has gone terribly wrong if the Fourth Amendment is read as giving license to a surveillance state. As we argue in our article, programs of broad and indiscriminate surveillance have deleterious effects on our individual development and our collective democratic processes. These concerns are familiar in the information privacy law context, where we have spent nearly fifty years talking about dataveillance and digital dossiers, but they have clear footing in the Fourth Amendment as well. More precisely, we argue that a fundamental purpose of the Fourth Amendment is to serve as a bulwark against the rise of a surveillance state. It should be read as denying law enforcement officers unfettered access to investigative technologies that are capable of facilitating broad programs of indiscriminate surveillance. GPS-enabled tracking is pretty clearly one of these technologies, and therefore should be subject to the crucible of Fourth Amendment reasonableness—at least on our technology-centered approach to quantitative privacy.