Carpenter v. United States: The Supreme Court Hands Privacy Advocates a (Limited) Victory

In Carpenter v. United States, 585 U.S. ___ (2018), the U.S. Supreme Court ruled that the government must get a warrant to obtain certain types of information from cell-phone providers.
  1. The Facts

There were a series of robberies at several different Radio Shacks and T-Mobile stores in the greater Detroit area (covering locations in both Michigan and Ohio). The FBI nabbed a suspect, who later confessed and turned informant. In doing so, the informant identified fifteen accomplices and provided phone numbers for some of the fifteen. The FBI then performed an examination of the informant’s phone and culled additional phone numbers beyond the fifteen identified. It is not clear from the Court’s opinion whether Carpenter was one of the original fifteen cited by the informant, or if Carpenter’s phone number was simply among the additional numbers culled by the FBI.

The FBI then obtained two court orders from two federal magistrates for Carpenter’s cell site location information (“CSLI”) under the Stored Communications Act, 18 U.S.C. §2703(d) (the “SCA”).

“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.” (Pp. 3.)

Of the multitude of suspects arrested, seven pegged Carpenter as the ringleader. Carpenter was charged with twelve counts total for six of the robberies. Carpenter moved to suppress the CSLI evidence, citing an expectation of privacy in the cell phone data. The district court denied the motion. Subsequent expert testimony placed Carpenter “right where the . . . robbery was at the exact time of the robbery.” P. 3, citing App. 131 (closing argument). Carpenter was convicted on eleven of the counts and sentenced to 100+ years in prison. The Sixth Circuit, claiming that Carpenter “shared” the location information with the respective telecommunications providers, affirmed under the third party doctrine. 819 F. 3d 880 (2016) (citing Smith v. Maryland, 442 U. S. 735, 741 (1979)). The third party doctrine states that there is no expectation of privacy when the information is “shared” with a third party, in this case, the telecommunications provider.


  1. The Opinion

The Supreme Court, in a 5-4 decision, reversed. Chief Justice Roberts sided with the Court’s four “liberals” and wrote a unified majority opinion (no concurrences). The dissent was as fractured as Eagle Ford, with each of the four “conservatives” writing their own dissenting opinions.

The majority focused on four areas: the Fourth Amendment & technology (pp. 4-15), the third party doctrine (pp. 15-17), the limitations of the opinion (17-18), and the standards for CSLI and the SCA (pp. 18-22).

The one-sentence summary of the case is: The government can get spying data, but not too much of it without a warrant. In other words, there are limitations on data fishing expeditions by the government. This is actually in tune with standard (civil) e-discovery practice, but is seemingly at odds with the third party doctrine previously promulgated by the Court itself. Is the third party doctrine dead? No, said the Court, but that doctrine must be sensitive to cultural use of technology and the implications of that technology in view of the original intent of the Fourth Amendment.

After a quick review of Fourth Amendment jurisprudence (pp. 4-6), the Court touched on the balance between the need for government surveillance capabilities and the privacies expected when the Fourth Amendment was adopted (pp. 5-7). Importantly, the majority opinion cited Justices Alito’s and Sotomayor’s concurring opinions in United States v. Jones, 565 U. S. 400 (2012) (the GPS tracking case), as well as Katz v. United States, 389 U. S. 347, 351 (1967) (“the Fourth Amendment protects people, not places”).

What technology trips Fourth Amendment protection? The Court wasn’t clear on that point. The dissent (particularly Justice Kennedy) said that there was no rubric in this case that prompted Fourth Amendment protection. The majority averred, stating that “[a]lthough no single rubric definitively resolves which expectations of privacy are entitled to protection, the analysis is informed by historical understandings “of what was deemed an unreasonable search and seizure when [the Fourth Amendment] was adopted.” Pp. 5-7, citing Carroll v. United States, 267 U. S. 132, 149 (1925). Perhaps to stave off the dissent, or for whatever reason, the majority distinguish cell-phone tracking information from other technologies heretofore considered by the Court. (Pp. 6-7.) Repeatedly, during the recitation of precedent, the Court focused on the character of the information (location or otherwise of the person) as well as the amount of information gathered.

In short, when participation in conventional society prompts the use of a technology that:

  • requires the cooperation of a third party; and
  • generates information about the person that would come under the purvey of the Fourth Amendment but for the third party,

then strict adherence to the third party doctrine is (pardon the pun) unwarranted, and the government needs a warrant to obtain said information.

The government can take solace from the fact that Chief Justice Roberts went out of his way to state:

“Our decision today is a narrow one. We do not express a view on matters not before us: real-time CSLI or “tower dumps” (a download of information on all the devices that connected to a particular cell site during a particular interval). We do not disturb the application of Smith and Miller or call into question conventional surveillance techniques and tools, such as security cameras. Nor do we address other business records that might incidentally reveal location information. Further, our opinion does not consider other collection techniques involving foreign affairs or national security.” (Pp. 17-18)


That certainly provides grist for more litigation.