"...In harder cases dealing with unfamiliar items such as communications and data, however, courts retreat to the Supreme Court’s “reasonable expectation of privacy” doctrine that emerged from Katz v. United States (1967). The Court has decided to review the important criminal-procedure and digital-privacy issues here.
...Cato and the Competitive Enterprise Institute, joined by Reason Foundation and the Committee for Justice, filed an amicus brief [in Carpenter v. United States] urging the Court to return to the text of the Fourth Amendment. The reasonable expectation of privacy test is outdated because it lacks a strong connection to the text and asks courts to conduct a sociological exercise rather than a judicial one. This is especially true in the context of new technology, where societal expectations have not been fully formed yet and will change based on the Court’s judgment, leading to circular reasoning..."
Read more by Ilya Shapiro in CATO AT LIBERTY...