As modern day technology continues to test the limits of many long-held constitutional precepts, the question before the Court in this case was whether the Government conducts a “search” under the Fourth Amendment when it accesses historical cell phone records that provide a comprehensive chronicle of the user’s past movements.

As Justice Roberts explained in his majority opinion: “The question we confront today is how to apply the Fourth Amendment to a new phenomenon: the ability to chronicle a person’s past movements through the record of his cell phone signals … Much like GPS tracking of a vehicle, cell phone location information is detailed, encyclopedic, and effortlessly compiled.”

More specifically, the Court addressed Government access to the millions of time-stamped records known as “cell-site location information” (“CSLI”), which the phone companies collect and store for their own business purposes and which can pin-point the location of anyone carrying a cellphone whether it is being used or not.

That question arose in a case involving a series of armed robberies of Radio Shacks and other stores in the Detroit area starting in 2010. Witnesses said Timothy Carpenter had planned the robberies, supplied guns and served as lookout, typically waiting in a stolen car across the street.

Based on that information, the prosecutors applied for court orders under the Stored Communications Act to obtain cellphone records for Carpenter and several other suspects. That statute permits the Government to compel the disclosure of certain telecommunications records when it “offers specific and articulable facts showing that there are reasonable grounds to believe” that the records sought “are relevant and material to an ongoing criminal investigation.” 18 U. S. C. §2703(d).

Federal Magistrate Judges issued two orders directing Carpenter’s wireless carriers—MetroPCS and Sprint—to disclose “cell/site sector [information] for [Carpenter’s] telephone[ ] at call origination and at call termination for incoming and outgoing calls” during the four-month period when the string of robberies occurred. The first order sought 152 days of cell-site records from MetroPCS, which produced records spanning 127 days. The second order requested seven days of CSLI from Sprint, which produced two days of records covering the period when Carpenter’s phone was “roaming” in northeastern Ohio.

Altogether the Government obtained 12,898 location points cataloging Carpenter’s movements—an average of 101 data points per day. Those records disclosed, inter alia, whether he had slept at home on given nights and whether he attended his usual church on Sunday mornings.

Carpenter was charged with six counts of robbery and an additional six counts of carrying a firearm during a federal crime of violence. Prior to trial, Carpenter moved to suppress the cell-site data provided by the wireless carriers.

He argued that the Government’s seizure of the records violated the Fourth Amendment because they had been obtained without a warrant supported by probable cause.

After the District Court denied his motion, Carpenter was convicted and sentenced to 116 years in prison.

On appeal, the Sixth Circuit affirmed in a decision reported at United States v. Carpenter, 810 F.3d 880 (6th Cir. April 13, 2016) (“Carpenter I”). That court reasoned that Carpenter lacked a reasonable expectation of privacy in the location information collected by the FBI because he had shared that information with his wireless carriers. Given that cellphone users voluntarily convey cell-site data to their carriers as “a means of establishing communication,” the court concluded that the resulting business records are not entitled to Fourth Amendment protection. (Carpenter I, id., at 888, quoting Smith v. Maryland, 442 U. S. 735 (1979)).

By a vote of 5-4, the Supreme Court reversed Carpenter I and remanded. Writing for himself and Justices Ginsburg, Breyer, Sotomayor and Kagan, Justice Roberts held that the Government’s acquisition from wireless carriers of a defendant’s historical cell-site location information was a search under the Fourth Amendment, which protects “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.”

In explaining that right, Justice Roberts noted that the Supreme Court has firmly established that “the Fourth Amendment protects people, not places.” Thus he explained: “When an individual ‘seeks to preserve something as private,’ and his expectation of privacy is ‘one that society is prepared to recognize as reasonable,’ we have held that official intrusion into that private sphere generally qualifies as a search and requires a warrant supported by probable cause.” In many ways, the instant decision represents a natural progression from a pair of recent decisions in which the Court expressed discomfort with allowing unlimited Government access to digital data.

In United States v. Jones, 565 U. S. 400 (2012), the Court limited the ability of the police to use GPS devices to track suspects’ movements; and in Riley v. California, 573 U.S. ___, 134 S. Ct. 2473 (2014), it required a warrant to search cellphones.

Thus, after tracing the development of the Court’s jurisprudence in the digital era, Justice Roberts wrote:

“Given the unique nature of cell phone location records, the fact that the information is held by a third party does not by itself overcome the user’s claim to Fourth Amendment protection. Whether the Government employs its own surveillance technology as in Jones or leverages the technology of a wireless carrier, we hold that an individual maintains a legitimate expectation of privacy in the record of his physical movements as captured through CSLI. The location information obtained from Carpenter’s wireless carriers was the product of a search. …

“In fact, historical cell-site records present even greater privacy concerns than the GPS monitoring of a vehicle we considered in Jones …When the Government tracks the location of a cell phone it achieves near perfect surveillance, as if it had attached an ankle monitor to the phone’s user.

“Moreover, the retrospective quality of the data here gives police access to a category of information otherwise unknowable. In the past, attempts to reconstruct a person’s movements were limited by a dearth of records and the frailties of recollection. With access to CSLI, the Government can now travel back in time to retrace a person’s whereabouts, subject only to the retention polices of the wireless carriers, which currently maintain records for up to five years. Critically, because location information is continually logged for all of the 400 million devices in the United States—not just those belonging to persons who might happen to come under investigation—this newfound tracking capacity runs against everyone. Unlike with the GPS device in Jones, police need not even know in advance whether they want to follow a particular individual, or when. . . .

“At any rate, the rule the Court adopts ‘must take account of more sophisticated systems that are already in use or in development.’ . . . As the number of cell sites has proliferated, the geographic area covered by each cell sector has shrunk, particularly in urban areas. In addition, with new technology measuring the time and angle of signals hitting their towers, wireless carriers already have the capability to pinpoint a phone’s location within 50 meters. “Accordingly, when the Government accessed CSLI from the wireless carriers, it invaded Carpenter’s reasonable expectation of privacy in the whole of his physical movements.”

The majority also held that the fact that the Government obtained the information from a third party did not overcome defendant’s claim to Fourth Amendment protection (as some of the dissenting judges argued).

Finally, the majority further held that a court order obtained by the Government under the Stored Communications Act, 18 U.S.C.S. § 2703(d), was not a permissible mechanism for accessing historical CSLI because the showing required under the Act fell well short of probable cause. Thus, it concluded that a warrant was necessary to obtain CSLI in the absence of an exception such as exigent circumstances.

The Court’s ruling clearly has implications for all kinds of personal information held by third parties, including email and text messages, internet searches, and bank and credit card records.

Therefore, Justice Roberts stressed that this ruling had limits. He wrote: “We hold only that a warrant is required in the rare case where the suspect has a legitimate privacy interest in records held by a third party.”  See: Carpenter v. United States, 138 S. Ct. 2206 (2018).

This article originally appeared in the June 2018 issue of Punch & Jurists and is reprinted with permission, with minor edits. Copyright, Punch & Jurists.

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