Substitution Effects: A Problematic Justification for the Third-Party Doctrine of the Fourth Amendment

In the past half-century, the Supreme Court has crafted a vein of jurisprudence virtually eliminating Fourth Amendment protection in information turned over to third parties - regardless of any subjective expectation of privacy or confidentiality in the information on the part of the revealer. This so-called “third-party” doctrine of the Fourth Amendment has become increasingly controversial in light of the growing societal reliance on the Internet in the United States, where nearly every transaction requires a user to turn information over to at least one third party: the Internet service provider (“ISP”). Citing the scholarship that has criticized the third-party doctrine would make for “the world’s longest law review footnote.” This essay instead focuses instead on a justification for the doctrine advanced by prominent computer crime scholar Orin Kerr. In his controversial essay The Case for the Third-Party Doctrine, Professor Kerr argues that the third-party doctrine is essential to preclude criminals from substituting private transactions involving third parties (particularly ISPs) for the criminals’ formerly public transactions, which were subject to police surveillance. This essay examines various descriptive and normative gaps that potentially undermine the “substitution effects” justification