In a landmark decision significantly affecting digital privacy, the United States Supreme Court, in Carpenter v. U.S., 585 U.S. ___, has held for the first time that a person has an expectation of privacy in the whole of his or her physical movements. In addition, it reframed the 40 year-old third party doctrine to permit a person to maintain privacy rights even though he has shared information with a third party, when the information is uniquely sensitive and personal.

The court also made clear that it will step in, when necessary, to ensure that the government’s power does not become excessive because of “seismic shifts in digital technology.” (Slip Op at 15). In the last few years the court has attempted to do so in the area of GPS surveillance (U.S. v. Jones, 565 U.S. 400 (2012)) and cell phone searches (Riley v. California, 573 U.S. ___ (2014)); search warrants are now required for both procedures. It has now held that when law enforcement seeks historical cell site location information (CSLI), this constitutes a search which, with a few exceptions, will also require a search warrant.