On June 22, 2018, the United States Supreme Court held in Carpenter v. United States that law enforcement agencies must obtain a warrant supported by probable cause to obtain historical cell-site location information (“CSLI”) from third-party providers. The government argued in Carpenter that it could access historical CSLI through a court order alone under the Stored Communications Act (the “SCA”). Under 18 U.S.C. § 2703(d), obtaining an SCA court order for stored records only requires the government to “offer specific and articulable facts showing that there are reasonable grounds.” However, in a split 5-4 decision, the Supreme Court held that the Fourth Amendment requires law enforcement agencies to obtain a warrant supported by probable cause to obtain historical CSLI.
In Carpenter, the FBI obtained a court order under the SCA for historical CSLI. These records were used to convict the defendant, Carpenter, of robbing a number of stores, including the cell phone provider that ultimately provided the relevant records. Carpenter argued that accessing his CSLI without a warrant constituted a Fourth Amendment violation. The government argued that historical CSLI constituted routinely collected business records protected by the Supreme Court’s third-party doctrine (established in U.S. v. Miller and Smith v. Maryland), which provided that the public did not have a reasonable expectation of privacy for certain records held by third-party service providers. Siding with Carpenter, however, the Court held, “A majority of the court has already recognized that individuals have a reasonable expectation of privacy in the whole of their physical movements…Allowing government access to cell-site records—which hold for many Americans the ‘privacies of life,’—contravenes that expectation.”
Chief Justice Roberts was joined in the majority opinion by Justices Ginsburg, Breyer, Sotomayor and Kagan. Justices Kennedy, Thomas, Alito and Gorsuch dissented, each offering separate dissenting opinions.