Shearman & Sterling LLP | Government Regulatory Enforcement Blog | Supreme Court Requires Law Enforcement To Obtain Search Warrants Before Accessing Certain Cell Phone Location Data<br >  
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  • Supreme Court Requires Law Enforcement To Obtain Search Warrants Before Accessing Certain Cell Phone Location Data
    On June 22, 2018, in a 5-4 ruling, the United States Supreme Court held that the government’s acquisition of certain cell-site location information (“CSLI”) kept by third parties constitutes a search under the Fourth Amendment that is generally subject to the search warrant requirement. Carpenter v. United States, No. 16-402, 585 U.S. __ (2018). Chief Justice Roberts authored the majority opinion, while Justices Kennedy, Alito, Thomas, and Gorsuch filed separate dissents.

    The case arose after Timothy Carpenter was charged with a series of robberies and related firearms crimes that occurred in 2011. To gather evidence against Carpenter, the government sought and received orders under the Stored Communications Act to compel selected telecommunications companies to disclose CSLI kept in the ordinary course of business through their having provided cellular service to Carpenter. See 18 U.S.C. § 2703(d) (permitting the government to compel disclosure of certain telecommunications records upon a showing of “specific and articulable facts” that provide “reasonable grounds to believe” the records sought “are relevant and material to an ongoing criminal investigation.”). The CSLI, which is routinely generated each time a cell phone transmits or receives data over a wireless network, included time-stamped entries that revealed approximately where Carpenter was located over the four-month period when the robberies occurred. At trial, Carpenter moved to exclude the CSLI, arguing that the Fourth Amendment required the government to first obtain a warrant upon a showing of probable cause. The district court, however, denied Carpenter’s motion, and Carpenter was convicted. On appeal, the Sixth Circuit affirmed, holding that the Fourth Amendment was not violated because Carpenter lacked a reasonable expectation of privacy in the CSLI he shared with his wireless carriers.

    The Supreme Court reversed the Sixth Circuit. In so doing, it characterized the facts as lying “at the intersection of two lines of cases,” both of which inform the correct result. First, the Court explained that Carpenter can have a legitimate privacy interest in his physical location. Although drivers on public roads cannot reasonably expect privacy from traditional surveillance, or even from certain electronic surveillance that conveys a limited amount of information over a limited period of time, the Court stressed that “more sophisticated surveillance” implicated different principles. Specifically, the Court noted that it had held that GPS tracking that remotely monitored a vehicle’s movement for 28 days implicated the Fourth Amendment, because (according to five justices) it defied reasonable privacy expectations for monitoring to occur over such a lengthy period and to track every movement of a vehicle. Roberts wrote that Carpenter’s case presented an even easier question because CSLI contains data on every movement of individuals who carry cell phones, not just their vehicles, and because historical CSLI is maintained by wireless carriers for periods of multiple years.

    Second, the Court noted that the facts implicated another line of cases: the “third-party doctrine.” The Court characterized this precedent as teaching that “a person has no legitimate expectation of privacy in information he voluntarily turns over to third parties.” According to the Court, however, the CSLI in Carpenter’s case was “qualitatively different” from the business records collected by the government in past precedent on the third-party doctrine because shifts in technology had made it possible to collect and store CSLI in granular detail over multi-year periods. The Court also noted that the rationale for the third-party doctrine—“voluntary exposure”—did not hold up for the CSLI in question because that information was not truly “shared.” Instead, the Court reasoned that carrying a cell phone is an almost indispensable part of participating in modern life, and that service providers log CSLI by automatic operation of the device without any affirmative acts on the part of cell phone users.

    Throughout the opinion, the Court emphasized that its decision was intended to be narrow, expressly reserving questions involving real-time CSLI and more limited types of CSLI for another day. Indeed, the Court expressly refused to disturb the prior application of any of its precedents, “or call into question conventional surveillance techniques and tools, such as security cameras.” Justice Alito, however, in an opinion joined by Justice Thomas, warned that the majority’s approach nevertheless threatened established law enforcement practices and, regardless, ensured that “a blizzard of litigation” will follow. Justices Kennedy, Alito, and Thomas also argued that the majority misconstrued the third-party doctrine, reasoning that Carpenter could not have any legitimate expectation of privacy in his CSLI because he neither owned nor controlled it. Ultimately, however, the opinion suggests that, as technology develops and companies collect data on users in more granular detail, the third-party doctrine will continue to yield to individuals’ legitimate expectations of privacy.