Whose line is it anyway? Probable cause and historical cell site data.

• Author: McKeown, Megan L.

"For the Fourth Amendment protects people, not places. What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. But what he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected. "

--Justice Potter Stewart (1)

INTRODUCTION

In most contexts, the Supreme Court has treated warrantless searches as presumptively unreasonable under the Fourth Amendment. (2) A prosecutor can rebut this presumption by demonstrating that the search or seizure was reasonable, meaning the state bears the burden of validating the warrantless search under one of the narrowly defined warrant requirement exceptions. (3) While a warrantless search of a home is presumptively unreasonable, (4) the Fourth Amendment's protection has not been extended to require a warrant to obtain a cell phone's location information. Privacy scholars have argued considerably over what showing the government must make in order to require cell phone providers to turn over the cell phone location information data they store. (5)

During the summer of 2014, the Eleventh Circuit split with the Fifth and Third Circuits on whether the government must show probable cause to retrieve historic cell site data from cell phone providers in order to confirm that a suspect was close to where a crime was committed. The Fifth and Third Circuits have held that probable cause is not required to retrieve such information, but the Eleventh Circuit held the opposite in United States v. Davis. (6) Some commentators have suggested this was a questionable interpretation of the Fourth Amendment. (7) Historical cell site data is retrieved from a process whereby the cell phone communicates with the service towers nearby, and the process continues so long as the phone is powered on. (8) As the cell phone user moves away from one tower and approaches another, the phone will re-register at the closer tower. (9) Monitoring these tower switches can "map the movements of particular cell phones, and, consequently, their users." (10)

Following the decisions in the courts of appeals, a unanimous Supreme Court held in Riley v. California (11) that the Fourth Amendment protects the contents of a cell phone from seizure without probable cause. (12) But Riley does not adequately resolve the issue of historical cell site data retrieval because obtaining the contents of a cell phone is distinct from knowing the phone's physical locations. (13) Even though the Riley decision does not reconcile the circuit split directly, it appears at least to support the Eleventh Circuit's effort to exclude cell phone data obtained without a warrant. Notwithstanding Riley, the Eleventh Circuit vacated its decision in September 2014 and has decided to rehear United States v. Davis en banc, revealing the importance and controversial nature of this issue. (14) The Fourth Circuit will consider the same issue on appeal after the district court's decision in United States v. Graham, (15) in which the lower court held that information voluntarily disclosed to a third party, i.e., the cell phone company, ceases to enjoy Fourth Amendment protection. This theory of disclosure to third parties is known as the third-party doctrine. (16) The third-party doctrine takes the view that under the Fourth Amendment, an individual "assume [s] the risk" that information will be disclosed to law enforcement when a person conveys that information to the third party. (17)

While the view of the Fifth and Third Circuits is still the majority rule, it is an open question whether improvements in technology have caused the public's understanding of a reasonable expectation of privacy to evolve. Although some judges may not favor allowing the retrieval of cell phone location information without probable cause, their hands may be tied by the law as it stands, unless Congress is moved to act.

The Fourth Amendment's plain language, which protects "[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures," (18) arguably does not address all technological changes, including electronic communications (as electronic communications are not "houses," "papers," or "effects"). The drafters of the Amendment could not have anticipated such advances in electronic communication. The statute at issue in the historical cell site data cases, the Stored Communications Act (SCA, (19)) has made it difficult for district courts to find that probable cause is required for information retrieval in the electronic context. (20) To obtain an order, the SCA only requires that

the governmental entity offer[] specific and articulable facts showing that there are reasonable grounds to believe that the contents of a wire or electronic communication, or the records or other information sought, are relevant and material to an ongoing criminal investigation. (21) The "specific and articulable facts" standard is accepted as a lower threshold than the probable cause requirement of the Fourth Amendment to obtain a warrant, (22) and challenges have been raised as to both the applicability of the statute to historical cell site location data and its constitutionality under the Fourth Amendment. (23)

Cell phones are unique in that they can offer an abundance of information about a person. As the Court recognized in Riley, a cell phone collects together "many distinct types of information ... that reveal much more in combination than any isolated record," and the "phone's capacity allows even just one type of information to convey far more than previously possible." (24) All of the information that cell phones pull together can allow one's private life to be reconstructed. (25) For example, the historical information from cell phone towers can be used to locate a person's position within several feet. (26)

This Note argues that the "specific and articulable facts" standard does not accord with the intent of the drafters of the Fourth Amendment to protect individuals' reasonable expectation of privacy. (27) Although allowing the government access to historical cell site data to use as evidence in a criminal proceeding aids law enforcement, legislators must recognize the risks that flow from allowing the government to retrieve cell phone location information without probable cause. At least one study suggests that the public is losing confidence in their ability to control personal information, ultimately creating public discomfort with and suspicion of government surveillance. (28) If Congress declines to amend the statute, the idea of a "big brother" government watching its people may disturb the sensibilities of the public. (29) In 2012, cell phone providers responded to over 1.1 million federal, state, and local law enforcement requests for cell phone records, (30) with the public largely remaining unaware of the volume of these requests.

Part I presents the Supreme Court's Fourth Amendment jurisprudence regarding this issue, while Part II highlights the analytical problems the circuit courts have faced in attempting to reconcile Supreme Court decisions in order to decide historical cell site data cases. Finally, Part III presents potential resolutions of the proper standard for historical cell site data retrieval and urges Congress to reexamine the SGA's "specific and articulable facts" standard to better comport with society's privacy expectations.

1. THE SUPREME COURT'S FOURTH AMENDMENT JURISPRUDENCE

   1. Early Fourth Amendment Jurisprudence

      The Supreme Court's original Fourth Amendment jurisprudence was heavily tied to common-law trespass. In Olmstead v. United States, (31) the Court held that attaching wiretaps to telephone wires on public streets was not a Fourth Amendment search because "[t]here was no entry of the houses or offices of the defendants." (32) The Supreme Court moved away from this exclusively property-based approach in Katz v. United States (33) when it held that "the Fourth Amendment protects people, not places." (34) In Katz, the attachment of an eavesdropping device to a public telephone booth in order to listen to and record the defendant's words was found to be a search and seizure within the Fourth Amendment. (35)

      Justice Harlan's Katz concurrence developed an influential two-pronged test to determine the scope of the Fourth Amendment's protection. First, a person must have "exhibited an actual (subjective) expectation of privacy," and second, society must consider the expectation to be "reasonable." (36) However, courts have since largely ignored, or at least deemphasized, the first prong and instead have given more weight to the second prong. (37)

      Even though Katz held that a telephone conversation from a public telephone is entitled to a reasonable expectation of privacy, the Court has not extended that Fourth Amendment protection to telephone numbers, even when dialed from an individual's private phone. (38) In 1979, the Court held in Smith v. Maryland (39) that a person has no reasonable expectation of privacy in information voluntarily turned over to a third party. There, police installed a pen register without a warrant in order to determine the identity of a person who had made threatening phone calls to a robbery victim, claiming that he was the one who robbed her. (40) The Court found no legitimate expectation of privacy regarding numbers dialed on a phone, as the numbers were turned over to a third party, the telephone company. (41) The Court further found that even if the defendant harbored a subjective expectation that the numbers would remain private, society was not prepared to recognize that expectation as "reasonable," because when the defendant conveyed the numerical information to the telephone company in the normal course of business, he assumed the risk that the information may be turned over to law enforcement. (42) Therefore, the Court...