Privileging Privacy: Confidentiality as a Source of Fourth Amendment Protection

58 Pages Posted: 2 May 2018 Last revised: 20 Feb 2019

Date Written: April 23, 2018


Police do not need a warrant to search information that we reveal to third parties. This so-called “third-party doctrine” is supposed to tell courts when our personal information is no longer private, and therefore not protected by the Fourth Amendment. In the modern world, the doctrine goes too far, leaving much of our most intimate information exposed. We have little choice but to trust third-parties like cell companies, internet service providers, email providers, and the like with most of the data we generate.

The root of the problem is the Supreme Court’s restrictive conception of privacy. As the third-party doctrine shows, the Court understands privacy to be a type of secrecy. Just as information is no longer secret when told, the Court thinks information is no longer private after it is shared. In response, scholars have tried to invent entirely new conceptions of privacy or have proposed overruling the third-party doctrine altogether.

There is no need for such drastic and unlikely measures. Anglo-American law already has an understanding of privacy, refined over a four-hundred-year tradition, that is up to the task. Long before privacy was important to Constitutional law, it was one of the central concepts for the common law of attorney-client privilege, which protects private communications between attorneys and clients. Importantly, the privilege takes privacy to be a kind of confidentiality, rather than secrecy. Confidences, unlike secrets, can be shared. As a result, attorney-client communications can remain privileged even after voluntary disclosure to third parties if appropriate steps were taken to preserve their confidentiality. Conceiving of privacy as a kind of confidentiality could help soften the bright-line of the third-party doctrine by recognizing when the presence of third parties like cell companies or email providers truly removes privacy interests, and, as importantly, when it does not. Without such a development, the third-party doctrine will not survive the Information Age — or our Fourth Amendment protections will not survive it.

Keywords: Privacy, Fourth Amendment, Attorney-Client Privilege, Carpenter

Suggested Citation

Diamantis, Mihailis, Privileging Privacy: Confidentiality as a Source of Fourth Amendment Protection (April 23, 2018). 21 U. Pa. J. Const. L. 485 (2018), U Iowa Legal Studies Research Paper No. 2018-23, Available at SSRN:

Mihailis Diamantis (Contact Author)

University of Iowa - College of Law ( email )

Boyd Law Building, rm. 442
Iowa City, IA 52242
United States

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