Private Searches in the Age of Big Data

Abstract

Dragnet surveillance is the bogeyman of Fourth Amendment law. But in today’s world, much dragnet surveillance — particularly related to data — is spearheaded by private actors, who increasingly perform the “first line of offense” in law enforcement investigation. As policing becomes more dependent on data and algorithms, this trend is only likely to intensify. Should private surveillance be categorically off-limits to Fourth Amendment scrutiny? Construed at face value, existing law appears to say yes. That answer, however, is both normatively and doctrinally implausible. In a world of “big data policing,” the Fourth Amendment’s state action requirement must be relaxed. The doctrinal test should focus on the functional role that private actors play in investigations — whether the private actor has effectively displaced, and come to substitute for, law enforcement labor — not on formalities of public and private. In fact, current doctrine already invites a distinction along these lines, though it has been sidelined in favor of a wooden “state agency” test. Once the Supreme Court’s private search canon is reconstructed, however, it becomes clear that the salient question — in both a descriptive and a normative sense — is whether law enforcement has been outsourced, not the precise legal relationship between private actors and law enforcement officials. One aspect of the question, instructive though not necessarily exhaustive, is whether the initial (private) surveillance has a dragnet character or not.