The Justices had the unenviable job of making the constitution — a document ratified in 1789 — apply to smart devices and criminal proceedings that include them. It’s an incredibly tricky task that requires a lot of cognitive gymnastics and hypotheticals involving Thomas Jefferson having a smartphone as he was drafting.
This past term, the courts ruled 5-4 in Carpenter v US, a case pertaining to the expectation of privacy that individuals can expect of location data their smartphones store. The facts of the case were generally mundane. Petitioner Timothy Carpenter was suspected of having involvement of a string of robberies of tech stores including RadioShack and T-Mobile in Ohio and Michigan. One of the four individuals apprehended confessed to the crime and turned his phone over to investigators. The investigators wanted to track a few of the numbers that the confessor had called at the times of the robberies. While they did not have sufficient evidence to get a warrant for the information, they did have enough under the Stored Communications Act, which has a much lower threshold for turning over information. By the SCA, individuals can file requests for information directly with the company that stores it — in this case, the companies who owned the cell towers. Timothy Carpenter was arrested after the investigators matched his phone number with the locations of the robberies.
After Carpenter was found guilty, he filed an appeal claiming that the courts didn’t have the appropriate permission to access his whereabouts via his phone. His appeal came on fourth amendment grounds of a reasonable expectation of privacy.
Most modern laws and rulings pertaining to information stored on cell phones are based on a “third party” ruling from 1976. A SCOTUS ruling that year determined that while a person does indeed have an expectation of privacy, a person surrenders that expectation when they bring in a “third party,” such as a telephone company or a service provider. In 1979, the courts ruled, the government could gather the length of a call, who was on a phone call, and its duration without a warrant, but the contents of the call would require a warrant.
In addition, the 1986 Stored Communications Act was designed to prohibit providers from handing out users’ data freely unless the government could prove that it needed the information requested. Notably, the SCA requires a lower level of “proof” than a warrant. It’s this loophole that investigators exploited in obtaining Carpenter’s physical whereabouts.
As the case worked its way up the court system, the question at the center was this: What if any expectation of privacy should smartphone users have? Does the government have carte blanche access to its citizens’ whereabouts at all times without a warrant?
On June 22, 2018, the courts handed down a 5-4 decision in favor of Carpenter. Penned by Chief Justice Roberts, the ruling noted that the courts continue to have trouble applying old laws to new toys, but that this narrow ruling was intended to keep the government from having, in effect, ankle monitors on all its citizens at all times. The dissent, written by now-retired Justice Kennedy, voiced concern that the majority decision would make it harder and more cumbersome for law enforcement and prosecutors to keep criminals off the streets.
The narrowness of the ruling means that the courts will certainly be hearing more cases about how privacy laws intersect with how modern citizens use their smartphones. Justice Sotomayor continues to be a visionary of privacy in the digital era, touring and giving talks on the topic. In a 2012 decision, Sotomayor famously noted that “physical intrusion is now unnecessary to many forms of surveillance,” and her foresight continues to guide her decision making on the bench.