Carpenter v. United States and the Digital Age
In April 2011, four men were arrested in relation to a string of armed robberies. After confessing, one of the individuals provided the FBI with his cell phone number, as well as the numbers of the other participants. To obtain "transactional records" for each of the phone numbers, the FBI applied for three court orders from magistrate judges using this information. The judges then granted the requests under the Stored Communications Act, 18 U.S.C. 2703(d). [1] According to that Act, when "specific and articulable facts show […] 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," the government may mandate the disclosure of specific telecommunications records. [2]
The records contained the date and time of calls and the estimated locations where calls started and finished, determined by their connections to cell towers—commonly referred to as cell-site location information (CSLI). [3] Utilizing the CSLI, the government charged Timothy Carpenter, who was associated with the above robberies, with, among other crimes, assisting and facilitating robbery affecting interstate commerce, contravening the Hobbs Act, 18 U.S.C. 1951. Carpenter sought to block the CSLI evidence by citing the Fourth Amendment, contending that the FBI required a warrant grounded in probable cause to access the records. The district court rejected the motion to suppress, and the Sixth Circuit upheld the decision. [4]
Carpenter represents a significant development in Fourth Amendment doctrine, as his case limited the application of the third-party doctrine in the digital age, and redefined what constitutes a “reasonable expectation of privacy.” [5]
In a 5-4 decision, the Supreme Court reversed the Sixth Circuit and held that the government’s acquisition of historical cell-site location information (CSLI) constituted a search under the Fourth Amendment in the case Carpenter v. United States. Writing for the majority, Chief Justice Roberts explained that CSLI provides an “intimate window” into a person’s life, revealing not only physical movements but also personal associations and patterns of behavior. [6] Unlike the limited data at issue in earlier third-party doctrine cases, such as bank records or dialed phone numbers, historical CSLI allows the government to reconstruct an individual’s movements across an extended period of time.
The Court emphasized several factors that distinguished CSLI from traditional business records. First, the quantity of data—127 days in Carpenter’s case—enabled sustained surveillance of his location. [7] Second, the Court rejected the argument that cell phone users meaningfully “voluntarily” disclose their location data, while noting that cell phones are indispensable to participation in modern society. Finally, the Court recognized that digital surveillance is relatively inexpensive and easily scalable, which increases the risk of widespread government monitoring.
At the same time, the Court declined to overturn the third-party doctrine entirely. Instead, it described its holding as “narrow,” applying specifically to historical CSLI. [8] This limitation left unresolved how lower courts should apply Carpenter to emerging forms of digital data collection. Subsequent cases in the lower courts demonstrate that judges have grappled with developing a consistent framework, often relying selectively on the factors identified by the Supreme Court.
Carpenter marks a significant development in Fourth Amendment jurisprudence because it acknowledges the implications of digital technologies for established privacy doctrines. While earlier precedents suggested that information shared with third parties receives no constitutional protection, the Court acknowledged that life in the 21st Century requires individuals to generate vast amounts of sensitive data simply by using essential technologies. [9][10] This recognition suggests a more contextual application of the third-party doctrine in cases involving digital data.
However, the decision also leaves important questions unanswered. Because the Court declined to articulate a clear doctrinal test, lower courts must determine how to weigh factors such as the revealing nature of data, the amount collected, and whether disclosure is truly voluntary. [11] Additionally, the continued application of the good faith exception may limit the practical impact of the ruling. As digital surveillance capabilities expand, Carpenter raises a broader constitutional question: whether the Fourth Amendment applies in an era where nearly every aspect of life leaves a digital trace.
Sources
Stored Communications Act, 18 U.S.C. § 2703(d). (1986)
Ibid
Carpenter v. United States, 585 U.S. (2018).
Ibid.
Ibid.
Ibid.
Ibid.
United States v. Miller, 425 U.S. 435 (1976).
Ibid.
Smith v. Maryland, 442 U.S. 735 (1979).
Tokson, Matthew. “The Aftermath of Carpenter: An Empirical Study of Fourth Amendment Law, 2018–2021.” Harvard Law Review.