The Normative Fourth Amendment

For decades, courts have used a “reasonable expectation of privacy” standard to determine whether a government action is a Fourth Amendment search. Scholars have convincingly argued that this test is incoherent, arbitrary, and incapable of protecting privacy against modern forms of surveillance. Yet few alternatives have been proposed, and those alternatives pose many of the same problems as the current standard.This Article offers a new theoretical approach for determining the scope of the Fourth Amendment. It develops a normative model of Fourth Amendment searches, one that explicitly addresses the balance between law enforcement effectiveness and citizens’ interests inherent in Fourth Amendment law. Drawing on Fourth Amendment jurisprudence and contextual privacy theory, it emphasizes surveillance’s concrete impacts, including its deterrence of lawful activities, interference with relationships and communications, and measurable psychological harms. The normative model’s pragmatic focus allows it to capture the fundamental harms and benefits of surveillance while remaining workable for courts.The normative approach is consistent with the language, history, and purposes of the Fourth Amendment, and its values are echoed throughout the relevant caselaw. It also has important practical advantages over current doctrine: it is adaptable to technological change, encompasses non-privacy harms such as coercion and discrimination, reflects Fourth Amendment values more fully than other approaches, promotes judicial transparency, and is better able to address large-scale surveillance programs. Further, the normative approach can help resolve a variety of difficult Fourth Amendment questions involving emails, internet browsing, smart home technology, financial records, household trash, and more