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Alabama Law Review





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Persistent surveillance technologies grant police vast new investigative capabilities. The technologies both monitor targeted areas and generate databases of searchable information about people, places, and patterns that can be connected and accessed for criminal prosecutions.

In the face of this growing police surveillance, courts have struggled to make sense of a fragmented Fourth Amendment doctrine. The Supreme Court has offered some clues that “digital may be different” when it comes to surveillance, but lower courts have been left struggling to apply old law to new technologies. Warrantless use of persistent surveillance technologies raises hard questions about when a “search” occurs and whether the Fourth Amendment should limit overbroad police collection.

This Article attempts to solve the persistent surveillance puzzle. First, it defines persistent surveillance technologies and explains why these policing systems represent a different privacy and security threat— one constitutionally distinguishable from traditional policing tools. Second, the Article examines the legal questions courts must ask in evaluating the Fourth Amendment implications of new persistent surveillance technologies used without a warrant. This Part synthesizes lessons learned from recent Supreme Court cases on digital surveillance and offers a new framework for future analysis. Third, this Article examines the technological framing questions courts must ask in evaluating these networked systems. Revealingly, how courts choose to define the scope, scale, and capacity of the technology itself— what I call the unit of surveillance—will shape the Fourth Amendment answers.

The long-term goal of this Article is to offer a Fourth Amendment framework for all future persistent surveillance technologies. The short-term project applies these principles to two vexing persistent surveillance puzzles recently before the federal courts involving aerial surveillance planes and long-term pole cameras.



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