Lior Strahilevitz & Matthew Kugler, The Myth of Fourth Amendment Circularity, 84 U. Chi L. Rev. 1747 (2017): “Our findings suggest that popular privacy expectations are far more stable than most judges and commentators have been assuming.” Meaning what? To me: People still maintain strong expectations of privacy despite having it eroded by business (and not government) largely without knowledge or effective consent. Yes, I gave a company information about me just to do business or own a cell phone, but I sure don’t expect them to share it with the government because it’s mine and I still consider it private.
This potential circularity gives rise to a practical problem. Once the state begins using an investigative technique, and especially once the courts authorize the state to do so, ordinary people’s expectations of privacy may adjust. Thus, even if people expected privacy in a context at some earlier point in time, subsequent actions by the government can erode these expectations, enabling the state to conduct invasive surveillance in the future without having to secure a warrant. If this understanding of expectations is correct, the Fourth Amendment provides little protection against a government that acts strategically; all it need do is move incrementally and publicize what it is doing. Further, the judicial determination of whether an expectation of privacy exists would be largely empty; even if the court gets the answer “wrong,” public expectations would soon adapt to make it “right.” For those who argue that the reasonableness of a privacy expectation should depend on whether the expectation is widely shared, this is an especially salient problem. If public expectations
are a function of whatever the Supreme Court said last, then the Court accounting for such expectations would result in it talking to itself.