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Tech & Sourcing @ Morgan Lewis


On June 5, 2017, the Supreme Court of the United States granted certiorari in Carpenter v. United States, a case in which the court will assess and decide the extent of the Fourth Amendment’s protection against a warrantless search and seizure of cell-site-location information (CSLI), which includes the GPS coordinates of each cell tower and the dates and times any cell phone connects to it.


In Carpenter, the FBI obtained CSLI from wireless carriers linked to suspect Timothy Carpenter’s cell phone in an attempt to place him at the sites of several robberies. However, the CSLI obtained was not only for those dates and times of the known robberies, but also included months of records detailing every location from which Carpenter made a call—and all of this was obtained without a warrant.

Carpenter, who is represented by the American Civil Liberties Union (ACLU), argues that his Fourth Amendment rights were violated when the FBI obtained the CSLI without a warrant. However, the FBI relied on the “third-party doctrine,” a legal theory used by law enforcement to access personal data without having to demonstrate probable cause. This would allow access to certain information collected by private businesses for providing services to customers without constituting a “search.”

The Third-Party Doctrine

The third-party doctrine is derived from 1970s case law and is based on the concept that when a person shares records or information with a third party, such as another person or a business, the person sharing forgoes any reasonable expectation of privacy with respect to such information.

Although the government and certain lower courts have applied the third-party doctrine to certain types of sensitive digital data, members of the Supreme Court have since disagreed. In her 2012 concurring opinion in United States v. Jones, Justice Sonia Sotomayor wrote, “It may be necessary to reconsider the premise that an individual has no reasonable expectation of privacy in information voluntarily disclosed to third parties. This approach is ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks."

The Decision’s Implications

In today’s expanding and ubiquitous digital environment, more and more personal and sensitive information, beyond CSLI, is being held outside of homes and on the servers and databases of third parties. Wireless carriers, internet service providers, and social media platforms already store vast amounts of personal communications and personal data, such as health information, financial and relationship statuses, and other day-to-day habits of users. The expansion of the Internet of Things may further increase the depth and breadth of information collected.

The Court’s decision in Carpenter could potentially set a precedent that has a major impact on technology users today and in the years to follow. It may not only determine whether law enforcement’s seizure of CSLI without a warrant violates the Fourth Amendment, but could also have further implications with respect to the extent to which the US Constitution protects against warrantless search and seizure of personal and private data collected and stored by service providers via evolving technologies generally.

This case has not yet been set for argument; we will continue to provide updates as they are made available.