Whether the government's acquisition, pursuant to a court order issued under 18 U.S.C. 2703(d), of historical cell-site records created and maintained by a cell­ service provider violates the Fourth Amendment rights of the individual customer to whom the records pertain.



Following a jury trial in the United States District Court for the Eastern District of Michigan, petitioner was convicted on six counts of aiding and abetting Hobbs Act robbery, in violation of 18 U.S.C. 1951(a), and five counts of aiding and abetting the use or carry­ing of a firearm during and in relation to a crime of vio­lence. The district court sentenced petitioner to 1395 months in prison. The court of appeals affirmed.

A. Cell-Site Records And The Stored Communications Act

1. Cellular telephones work by establishing a radio connection with nearby cell towers (or 'cell sites').  Al cell tower is a large antenna that emits a radio frequency" to cell phones within the tower's coverage area. "Individual towers project different signals in each direction or 'sector,'" typically with three sectors per tower. If a provider does not have towers covering a particular area, the provider may enter into a roaming agreement to use another provider's towers. In rural areas, a tower's coverage might reach as far as 20 miles. In an urban area like Detroit, where most of the robberies at issue occurred, each cell site covers typically anywhere from a half-mile to two miles.

When an individual places or receives a call on a cell phone, the phone scans its environment and connects to the cell site with the best signal, which will typically be the tower closest to the phone or in its direct line of sight. Factors other than distance may influence signal strength, including buildings, to­pography, and the time of year. During the call, the phone and tower transmit signals to each other to maintain the connection, and the phone may switch to a new tower if the signal strength fluctuates or the phone moves.

Cell-service providers typically log and store cer­tain call-detail records of their customers' calls, includ­ing the date, time, and length of each call; the phone numbers engaged on the call; and the cell sites where the call began and ended. No law re­quires providers to create or maintain cell-site records; instead, providers retain those records in the ordinary course of business for their own purposes. Those purposes include finding weak spots in the pro­viders' networks and applying roaming charges. In addition, providers may sell aggregated cell-site data they collect or otherwise use that data in business ven­tures unrelated to providing cell-phone service. Providers in the United States disclose their collection and use of cell-site data in their privacy policies

2. The Stored Communications Act (SCA), authorizes the government to obtain cell ­service providers' records pertaining to their subscrib­ers under specified circumstances. As relevant here, the government may require a provider to disclose a record or other information pertaining to a subscriber (not including the contents of com­munications) through a court order for such disclo­sure. To obtain a court order, the government must offer specific and articulable facts showing that there are reasonable grounds to believe that the rec­ords or other information sought are relevant and ma­terial to an ongoing criminal investigation. On the provider's motion, the court may quash or modify an order, if the infor­mation or records requested are unusually voluminous in nature or compliance with such order otherwise would cause an undue burden. In addition, a pro­vider may raise a Fourth Amendment challenge to ensure compliance with consti­tutional limits on the use of compulsory process.

B. The Present Controversy

1. Beginning in December 2010, petitioner and his co-conspirators committed a string of armed robberies at Radio Shack and T-Mobile stores in Ohio and Michi­gan. Petitioner typically organized the robberies, supplied the guns, and acted as a lookout. On petitioner's signal, a group of robbers en­tered the store, brandished their guns, herded custom­ers and employees to the back, and ordered the employ­ees to fill the robbers' bags with new smartphones. After each robbery, the team met nearby to dis­pose of the guns and getaway vehicle and sell the stolen merchandise.

2. a. In April 2011, police arrested four of peti­tioner's co-conspirators, and one of them confessed that the group had robbed nine different stores in Mich­igan and Ohio between December 2010 and March 2011, supported by a shifting ensemble of 15 other men who served as getaway drivers and lookouts. Based on that information, the government applied to federal magistrate judges for court orders pursuant to the SCA. As relevant here, those applications sought orders directing MetroPCS and Sprint to dis­close non-content records for a cell-phone number that petitioner used, including cell site information for pe­titioner's telephone at-call origination and at-call ter­mination for incoming and outgoing calls. 4a. Specifically, the government requested 152 days of his­torical cell-site records from MetroPCS, spanning the period when the string of robberies occurred in Detroit between December 2010 and April 2011. The government sought seven days of records from Sprint, linked to the date of a robbery in Warren, Ohio, where MetroPCS has a roaming agreement with Sprint.

The magistrate judges issued the requested orders.

MetroPCS then produced 127 days of cell-site records and Sprint produced two days of records for petitioner's phone number. The records showed the towers petitioner's phone connected to when it made and received calls, but did not contain any cell-site in­formation for text messages or for times when peti­tioner's phone was turned on but was not being used to connect a call.

From the cell-site records, as well as MetroPCS and Sprint records identifying the locations of their towers, the government could infer the approximate location of petitioner's phone when calls were connected to it around the time of the robberies. Because the cell sites covered areas extending be­tween one-half mile and two miles in length, however, the government could determine the location of peti­tioner's phone only within a 3.5 million square-foot to 100 million square-foot area, as much as 12,500 times less accurate than GPS data. The government ultimately determined that peti­tioner's phone connected to cell towers in the general vicinity of the sites of four robberies around the times those robberies occurred.

b. Petitioner was indicted on six Hobbs Act counts and six firearms counts. Before trial, pe­titioner moved to suppress the cell-site records. Petitioner argued that MetroPCS's and Sprint's production of their business records constituted a Fourth Amendment search of petitioner that could be conducted only pursuant to a warrant supported by probable cause.

The district court denied the motion to suppress.

The court found no legitimate ex­pectation of privacy in cell site data, and fur­ther held that suppression would not be an appropriate remedy even if a warrant were required "because the agents relied in good faith on the SCA in obtaining the evidence.

c. The case proceeded to trial, where seven accom­plices testified about petitioner's involvement in the robberies. The government also intro­duced videotapes and eyewitness testimony placing pe­titioner near the relevant robbery scenes.

In addition, FBI Special Agent Christopher Hess of­fered expert testimony about the cell-site data for peti­tioner's phone. Agent Hess explained that petitioner's providers recorded tower information only when the phone was "active," meaning "engaging in a call." If you dial a number and you hit send, that tower information is populated in the call detail record, but records are not created when the phone is just in al pocket and not making or receiving calls. "The parties stipulated and agreed that the telephone call detail records from Metro PCS and Sprint" were authentic and accurate business records of these com­panies.

Based on those records, Agent Hess identified eight calls that occurred around the time of four robberies. He presented maps of the towers that connected those calls to demonstrate that petitioner's phone was within a half-mile to two miles of the crime scenes. But Agent Hess could not offer "any opinion about exactly where a phone was at any particular time" within each tower's coverage area. He acknowledged that he could not determine from the cell-site records whether petitioner's phone was at a specific parking lot or intersection; whether the phone was north or south of a store; whether the phone had con­nected to a particular tower based on proximity or other "variables, such as battery strength; who was actually using the phone at the time that the call was made; or why the phone was lo­cated within a particular tower's coverage area at a par­ticular time. Agent Hess acknowledged that his analysis of cell-site records was not an exact sci­ence.

The jury convicted petitioner on all the Hobbs Act counts and all but one of the firearms counts. The district court sentenced petitioner to 1395 months in prison.

3. The court of appeals affirmed. As relevant here, the court of appeals rejected pe­titioner's Fourth Amendment challenge, holding that the government's acquisition of the cell-site records was not a search of petitioner.

The court of appeals emphasized that petitioner lacks any property interest in cell-site records cre­ated and maintained by his wireless carriers. As the court explained, MetroPCS and Sprint gathered information about which of their towers con­nected petitioner's calls in the ordinary course of busi­ness for their own purposes, such as to find weak spots in their network and to determine whether roam­ing charges apply. 

The court of appeals further concluded that peti­tioner had no reasonable expectation of privacy in those business records. The court relied on Smith v. Maryland (1979), which held that the police's installation of a pen register - a device that tracked the phone numbers a person dialed from his home phone was not a search because the caller could not reasonably expect those numbers to remain private. Because Smith 'voluntarily conveyed numerical information to the telephone com­pany and exposed that information to its equipment in the ordinary course of business, the numerical infor­mation was not protected under the Fourth Amend­ment. The court of appeals concluded that the same reasoning applied to cell-site records because cell-phone users voluntarily convey in­formation to their providers about their phones' prox­imity to particular towers as a means of establishing communication when they place or receive calls.

The court of appeals observed that "whether a de­fendant has a legitimate expectation of privacy in cer­tain information depends in part on what the govern­ment did to get it." Because this case involves business records obtained from a third party, the court found any expectation of privacy to be dimin­ished. The court further emphasized that the cell-site location data was "as much as 12,500 times less accurate" than GPS data and contained only "rout­ing information" that "said nothing about the content of any calls."

The court of appeals noted that, in enacting the SCA, Congress struck a balance by requiring the govern­ment to show 'reasonable groundsŐ but not 'probable cause' to obtain" cell-site records. The court observed that  "Congress is usually better equipped than courts are to answer the empirical questions that new technologies present." The court concluded that these concerns favor leaving undisturbed the Congressional judgment reflected by the SCA's middle ground approach be­tween full Fourth Amendment protection and no pro­tection at all.


I. The government's acquisition of cell-site records from MetroPCS and Sprint did not constitute a Fourth Amendment search of petitioner.

A. Petitioner has no legitimate expectation of pri­vacy in the business records his providers made of the cell towers used to route calls to and from his cell phone. This Court has long held that an individual cannot in­voke the Fourth Amendment to object to the govern­ment's acquisition of a third party's records that contain information about the individual

The third-party doctrine applies here. Petitioner had no subjective expectation of privacy in his provid­ers' records of the towers used to connect his calls. Cell­phone users are aware that they must be in a tower's coverage area to use their phones, and they must under­stand that their provider knows the location of its own equipment and may make records of the use of its tow­ers. And any subjective expectation of privacy would not be objectively reasonable. Cell-phone users volun­tarily reveal to their providers information about their proximity to cell towers so the providers can connect their calls. Users cannot reasonably expect that the providers will not reveal that business information to the government.

Contrary to petitioner's suggestion, cell-site records are not more sensitive than the records of phone num­bers dialed and banking records at issue in Smith and Miller. Inferences about location drawn from cell-site information are far less precise than GPS data and do not permit a detailed reconstruction of a person's move­ments. And in any event, the third-party doctrine does not turn on what information the government acquires and how sensitive that information is, but rather on how the government acquires the information. Seeking in­formation about a suspect from a third-party witness does not amount to a Fourth Amendment search of that suspect, no matter how revealing or incriminating the evidence may be. Nor was petitioner's action in convey­ing information about his proximity to cell towers less "voluntary" than the defendants' actions in Smith and Miller. In those cases, like this one, individuals were required to reveal information about themselves to use an important service provided by a business that was a ubiquitous part of modern society.  

Cell-service providers' use of technology does not justify a new Fourth Amendment rule. This case in­volves a traditional procedure used for centuries: com­pulsory process to a third party. The relevant change is not in government conduct, but in the actions of pri­vate providers in creating cell-tower networks and re­cording information about the networks' use. But a pri­vate actor's decision to acquire and record information is not a subject of Fourth Amendment protection.

Petitioner suggests that if the third-party doctrine is applied here, it would permit unregulated government collection of all information in a third party's hands, in­cluding email. That is incorrect. Email is routed through a provider, and its contents, like those of a sealed letter in the mail, may remain private. But cell­tower information is sent to the provider and used in its own business; it falls within the traditional third-party doctrine. Moreover, adherence to the third-party doc­trine does not eliminate all constitutional limitations on collection of data. Providers may invoke their own Fourth Amendment rights to object to compulsory pro­cess that exceeds legislative authorization, sweeps too broadly, or imposes undue burdens. The sensitivity of customer information may inform that calculus. The First Amendment and equal protection principles also protect against abuses. And if businesses' possession of great quantities of digital information raises new pri­vacy concerns, legislatures are well positioned to ad­dress them.

B. Petitioner was not subject to a trespassory search under United States v. Jones (2012). He can establish no protected interest in the providers' cell-tower records, and his reliance on posi­tive law to claim such an interest lacks merit.

II. If the government's acquisition of cell-site records amounted to a search of petitioner, it was con­stitutionally reasonable.

A. Under longstanding Fourth Amendment princi­ples, the government's use of compulsory process to ob­tain records does not require a warrant. Section 2703(d) falls within that tradition and in fact raises the bar from a subpoena by requiring a specific factual showing and a court order, thereby adequately protecting any expec­tation of privacy a customer could assert in cell-site rec­ords.

B. Applying standard Fourth Amendment balanc­ing principles leads to the same conclusion. Any privacy interest in third-party business records is diminished. And the government has a compelling interest in obtain­ing cell-site records to identify suspects, clear the innocent, and obtain information in the preliminary investi­gation of criminal conduct. Deference to Congress's judgment is appropriate in this new technological context.

III. If the Court concludes that a warrant is re­quired to obtain some cell-site records, it should hold, as petitioner concedes, that requests for short-term cell-site records fall outside that rule. Here, that prin­ciple would validate the request for seven days of rec­ords from Sprint, as that is well within the range of or­dinary visual surveillance of a person suspected of a crime.



The judgment of the court of appeals should be affirmed.