How the SCOTUS cellphone location data case could impact police searches and digital privacy

Decision could affect not only how the Fourth Amendment applies to police searches in the digital age, but also impact NSA surveillance and privacy rights

On November 29, the Supreme Court heard arguments in Carpenter v. U.S. about whether police need a warrant to obtain cell phone location data. Its decision could significantly affect not only how the Fourth Amendment applies to police searches in the digital age, but could also impact NSA surveillance and privacy rights in an era of evolving technology. 

The case

In April 2011, police arrested four men in connection with a series of armed robberies. One of the robbers confessed and gave the FBI his cellphone number and the numbers of the other participants.

The case might become a broadly decided watershed for the Fourth Amendment in the digital age.
The case might become a broadly decided watershed for the Fourth Amendment in the digital age. (Photo/Pixabay)

The FBI used this information to get a court order under the Stored Communications Act (SCA) for cellphone records that showed the movements of the suspects for a 127-day period. The SCA authorizes as such a court order based on “specific and articulable facts showing ... reasonable grounds to believe that ... the records or other information sought, are relevant and material to an ongoing criminal investigation” – a showing that is less than probable cause.

Carpenter moved to suppress the government's cellphone evidence arguing that the FBI needed a warrant to obtain the records. The trial court denied the motion and Carpenter was convicted as an accomplice to the robberies based, in part, on the location data.

Oral argument

Arguing for Carpenter, the ACLU placed heavy reliance on U.S. v. Jones (2012) in which the Supreme Court decided 9 – 0 that police violated the Fourth Amendment when they surreptitiously installed a GPS tracking device on a car driven by a suspected drug dealer without a warrant.

I’ve previously written that while the Jones decision was unanimous, the opinion was not clear cut. Five justices based their decision on the physical trespass committed by the police in placing the GPS.

Four justices based their decision on the Fourth Amendment’s broader “reasonable expectation of privacy.” While acknowledging that police surveillance in public places that produced the same information as a GPS was constitutional, this concurring opinion noted that historically resource allocation limited such surveillance to exceptionally important investigations. But the advanced technology of the GPS let the police cheaply and easily conduct 24/7 surveillance, which violated citizens’ reasonable expectation of privacy against government intrusion absent a warrant.   

The Government argued that Jones was not controlling in Carpenter’s case because the data was obtained from a third-party cellphone service provider to which Carpenter had voluntarily provided the information. Accordingly, the Court’s decisions in Smith v. Maryland and United States v. Miller – which held that people are not entitled to an expectation of privacy in information they voluntarily provide to third parties – should govern. In Smith the information was phone records revealing numbers Smith had dialed. In Miller the government had obtained checks and deposit slips Miller had given to his bank.


In her concurring opinion in Jones, Justice Sotomayor wrote that today’s technology may soon have the Court reconsidering the premise that a person has no reasonable expectation of privacy in information voluntarily disclosed to third parties. A look at oral argument in Carpenter indicates the Court is doing just that.

Sotomayor discussed at length how pervasive cellphones have become – young people take them to bed, others take them into public restrooms.

“It’s an appendage now for some people. If it’s not okay to put a beeper into someone’s bedroom, why is it okay to use the signals that phone is using from that person’s bedroom, made accessible to law enforcement without probable cause?”

She heeded the survey argued by Carpenter’s attorney that most Americans have a privacy expectation in their location data. She also noted that the “third-party doctrine” had never been absolute. The Court had limited it in Ferguson when it held the police couldn’t get medical records without consent or a warrant even though a patient had provided the information to a hospital. 

Technology isn’t the only thing that’s changed since the Jones decision. So has the makeup of the Court. In Jones, Justice Scalia was among those who decided the case on the narrow basis of the physical trespass in attaching the GPS.

Justice Gorsuch replaced Scalia and, at oral argument in Carpenter, he pressed the government on the notion that the data was “property” of the cellphone customer and not like information from a witness, as the government had argued. If the Court concluded the data was property if could not be seized absent a warrant under a strict interpretation of the Fourth Amendment. Gorsuch found support for his “property” notion in the Wireless Communication and Public Safety Act, which provides that telecommunications carriers have a duty to protect the confidentiality of proprietary information of, and relating to … customers.  

The Supreme Court might decide the Carpenter case narrowly. Carpenter’s attorney suggested the Court could rule for him without overturning Smith completely by holding the government could obtain 24 hours of location data with the SCA, and use that to help build probable cause, but not over four months’ worth.

The Fourth Amendment in the digital age

The case might also become a broadly decided watershed for the Fourth Amendment in the digital age based on both a liberal and conservative theory. The more liberal justices might find a reasonable expectation of privacy in electronic data that would require the government get a warrant before seizing 24/7 surveillance data for an extended period of time. The conservative justices might decide cellphone location data is property requiring a warrant before seizing it.

Stay tuned. A decision should be announced in late June 2018. In the meantime, check with your local prosecutor before obtaining any cell-site location information for more than a 24-hour period.

Recommended for you

Copyright © 2023 Police1. All rights reserved.