75 Am. U. L. Rev. 395 (2025).

Abstract

There is a hydraulic relationship between Fourth Amendment rights and remedies. When rights expand, remedies shrink, and vice versa. That makes good sense. At its heart, the Fourth Amendment requires striking a reasonable balance between the competing interests of citizens and their government. Expanding rights by, say, adopting a more expansive definition of “searches,” or applying the Fourth Amendment to a new category of government conduct, compromises government interests. When this happens, courts can, and should, bring things back into balance by adjusting remedies.

Sometimes the Court is cognizant of this hydraulic relationship. When the Court expanded Fourth Amendment rights to encompass administrative searches, it preserved hydraulic equipoise by allowing the political branches to design bespoke alternatives to the warrant requirement. Similarly, when the Justices expanded rights by bringing the Fourth Amendment to bear on street encounters between police and citizens, they accommodated government interests by withdrawing the warrant and probable cause requirements. But sometimes the Justices are maddeningly blind to Fourth Amendment hydraulics. For example, in United States v. Katz, the Court expanded Fourth Amendment rights by broadening the definition of “searches,” but it also held fast to the warrant requirement. That created a hydraulic crisis the Justices eventually resolved by creating the third- party and public observation doctrines, effectively clawing back rights.

The Supreme Court’s inattention to Fourth Amendment hydraulics has left the Justices and lower courts ill equipped to contend with new and emerging technologies like networked surveillance cameras, aerial surveillance, facial recognition, and artificial intelligence (AI). These technologies primarily serve government interests when they are deployed programmatically to surveil “either the public at large or a particular class of regulated but otherwise law-abiding citizens.” By definition, programmatic surveillance cannot satisfy the demands of the warrant requirement because it is suspicionless and prospective. So, if the only available remedy is a warrant requirement, then courts face a dilemma: they can expand rights by holding that programmatic surveillance is a “search,” which would deny political leaders and police access to important law enforcement tools; or they can hold that these technologies do not conduct “searches,” threatening citizens’ privacy and security interests by granting government agents unfettered discretion to deploy and use these powerful surveillance tools. Neither option seems “reasonable,” which is the touchstone of the Fourth Amendment. What to do?

One of the best ways to escape a dilemma is to find a third path. That is what courts should do as they consider the Fourth Amendment regulation of programmatic surveillance technologies. Specifically, courts should recognize that these technologies conduct “searches.” Having stated the obvious, courts should entertain alternatives to the warrant requirement that strike a reasonable balance among the competing interests at stake. This Article charts the way by offering a novel constitutional framework for regulating the deployment and use of programmatic surveillance technologies that achieves a reasonable balance between the legitimate interests of those who want to use these technologies and those subject to surveillance.

* Jacob A. France Professor, University of Maryland, Carey School of Law. My thanks to those who commented on this project at various stages including Danielle Citron, Barry Friedman, Jennifer Granick, Stephen Henderson, Orin Kerr, Michael Mannheimer, The Hon. Stephen Smith, and those who offered comments during presentations at the Federal Judicial Center, Privacy Law Scholars, and the University of Maryland. I am also in debt to Claire Rattan and her colleagues at the American University Law Review for their patience, faith, insight, and tireless work. Generative artificial intelligence played no role in the research and writing of this Article.