Opinion of the Court in Carpenter v. United States
Police Access to Cell-Site Records Does Require a Search Warrant
A person does not surrender all Fourth Amendment protection by venturing into the public sphere. To the contrary, “what [one] seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.” — Katz v. United States (1967). A majority of this Court has already recognized that individuals have a reasonable expectation of privacy in the whole of their physical movements. Prior to the digital age, law enforcement might have pursued a suspect for a brief stretch, but doing so “for any extended period of time was difficult and costly and therefore rarely undertaken.” —…
