Rachel Levinson-Waldman, Hiding in Plain Sight: A Fourth Amendment Framework for Analyzing Government Surveillance in Public, 66 Emory L.J. 527 (2017):
Over the last several decades, the range and capabilities of easily available technologies have expanded at an astonishing pace. The beeper gave way to the flip phone, which has largely been replaced by the “smartphone,” a mini-computer that fits in the palm of your hand and is more powerful than the desktop machine of the 1980s. Paper maps are increasingly rare, replaced by built-in Global Positioning System (GPS) devices or the ubiquitous smartphone. The days of having to keep change in a glove compartment to pay a toll attendant are long past; instead, an EZ-Pass reader enables drivers to travel seamlessly across multiple states and pay the charges directly from an online account.
These and other technologies, which are valuable to civilians and law enforcement alike, also enable a granular view of citizens’ movements and associations in public over long periods of time at a relatively cheap cost. The 2002 movie Minority Report, which seemed wildly futuristic at the time, effectively predicted many of the technologies now available to police at the click of a button: drones, facial recognition scanners, vehicle trackers, and more.
Where law enforcement is involved, these powerful new technologies also raise questions about how their use can be harmonized with the U.S. Constitution. The Fourth Amendment guarantees “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” Under what circumstances does an eye in the sky (or on a pole, or inside your phone) constitute a search under the Fourth Amendment—and thus presumptively require a warrant—when it is used for public surveillance?
It seems inconceivable that the Founders, who could fairly be described as obsessed with Americans’ right to be let alone, could have envisioned, let alone endorsed, the degree and depth of intrusion into individuals’ lives that is enabled by present-day surveillance technologies. At the same time, it is notoriously difficult to articulate when surveillance in public works a constitutional violation and when it is simply the price for leaving the house. While the judiciary is nowhere near consensus, courts are finding that some public manifestations of this new, digitally-enabled tracking are so inimical to any standard notions of privacy that the Fourth Amendment imposes limits on their use, as discussed in further detail below.