I wish I had listened to the first half of Monday’s Supreme Court argument Chatrie v. United Statescase asking when police can use cell phone data to determine who was near a crime scene, I would be convinced that the Court is about to significantly limit Americans’ right to privacy.
Many of the justices’ questions to Adam Unikowsky, the attorney for a criminal defendant who was convicted of bank robbery, seemed to cast doubt on Unikowsky’s claim that the Constitution severely limits the government’s ability to track people through their cellphones. Some judges even seemed likely to overturn it Carpenter v. United States (2018), a landmark case suggesting that police must obtain a warrant before obtaining cell phone data showing a person’s past whereabouts.
But in the second half of the argument, after Justice Department attorney Eric Feigin took the stage, many of the justices seemed more concerned about some of the ramifications of Feigin’s arguments.
As Chief Justice John Roberts pointed out shortly after Feigin began his argument, if the government has the power to track people using their cell phones, it could potentially learn the identity of everyone who attended a certain religious service, or everyone who attended a certain political rally. Meanwhile, several other justices seemed concerned that the attorney general’s arguments would allow police to comb through many people’s emails, or their personal calendars and photos, without first obtaining a warrant.
Given these concerns raised by the judges, it seems likely that the Court will issue a precautionary ruling Chatrie – one that reads Carpenter requiring the police to always obtain a warrant before attempting to track someone using their cell phone. He said, the police inside Chatrie in fact, it got the script. And the Court can say that the consent in this case was consistent with the Constitution.
Chatriein other words, it is likely to be a relatively narrow decision. The court seems likely to maintain existing privacy protections against police searches, but it is unlikely to expand them in any significant way.
“Geofence” permissions, explained briefly
Special legal question in Chatrie it involves “geofence” permissions.which are warrants that allow the government to learn who was in a certain area at a certain time. Usually, it is possible for the police to discover this information because mobile phone companies and software vendors such as Google often track the location of individuals’ phones.
In Chatriepolice obtained a warrant asking Google to hand over information about who was near a bank in Midlothian, Virginia, within an hour of a bank robbery. The document drew a 150 meter perimeter around the crime scene which included a nearby bank and church. Google had this information about some of its users because of an optional feature known as “my location history,” which can be used to pinpoint users’ location with incredible accuracy — but only for users who have opted in to the service.
The Court’s decision in Chatrie it is likely to be different, and unlikely to disrupt existing law.
The document also set out a three-step process that limited the amount of information police could obtain about each cell phone user who was within this geofence. In the first step, Google provided anonymous information to 19 people who were near the bank during the relevant period. Police sought additional location information on nine of these individuals and, after reviewing that additional information, located and received identification on three of these individuals. One of the three was Chatrie.
This document therefore placed significant restrictions on what information could be obtained by the police. The data was not disclosed until the final stage of the investigation, and the police knew the identity of only a small percentage of the total number of people who were present around the robbery.
At the same time, the document did not ask a judge or magistrate to decide whether the police had the right to reduce the original 19 people to nine, or less than three whose identities were revealed. Google was responsible for determining whether to turn over this additional information. At least some judges seemed upset by this fact on Monday, and may decide that the warrant would only be allowed if the police were required to go back to the judge and get permission to limit the search.
Three ways in which the Court can decide Chatrie
In general, the Court seemed to be divided into three groups Chatrie. The pro-police group, which includes Justices Clarence Thomas and Samuel Alito, appeared eager to slow down. Carpenter and making it easier for the government to track people without first obtaining consent.
As Alito said, Carpenter involved the same search, but one that was technologically different from the one in question Chatrie. In Carpenterthe police determined the suspect’s location by tracking which cell phone towers or other “sites” their phones were communicating with at various times. This information is less accurate than the GPS tracking data that Google had Chatriebut it is also news that, in Alito’s words, the cell phone user “has no choice but to disclose.”
Alito’s argument was that Chatrie could turn off the feature in most Google apps that allowed Google to track his location, but no cell phone user can block his phone from communicating with mobile sites unless he turns off the phone entirely. Carpenterunder Alito, it would only require a warrant if the police want to obtain information that the cell phone user cannot choose not to disclose.
As a practical matter, this would mean that the government would have unlimited power to track people’s movements, as long as it relies entirely on services like Google Maps or Uber, where users can prevent services from tracking their precise location.
Shortly after Feigin began his argument, however, several senior justices indicated that they were not buying Alito’s argument. Roberts expressed concern about police learning the identity of everyone who attends a particular church. Justice Neil Gorsuch pointed out that people also sometimes voluntarily share their personal emails, photos, and calendars with Google, and expressed concern that the government’s legal arguments would allow police to obtain that information without a warrant as well.
Judge Amy Coney Barrett, who also asked some questions that seemed to support the government’s position, seemed annoyed when he realized that the Justice Department’s argument would not only allow the police to track someone when they enter a private residence, but also especially if someone entered the bedroom of the residence.
That said, it seems unlikely that the Court will impose significant restrictions on the government’s ability to access geographic data as long as they obtain a warrant first. Judge Ketanji Brown Jackson, a former public defender who often sympathetic to the rights of criminal defendantshe made it clear that he saw no problem with the warrant allowing police to know which 19 people were close to the bank robbery – although he would likely support additional sanctions once police seek more information about some of these people.
Judge Brett Kavanaugh, meanwhile, suggested that a perimeter fence permit is valid as long as it limits the “geographical and temporal scope” of the search. The police, in other words, can find out who was in a narrowly defined area within a short period of time, but the Constitution may not allow the constant search of, say, everyone at a political demonstration that included many city blocks and that lasted all day.
All that is a long way of saying that the decision of the Court in Chatrie it is likely to be different, and unlikely to disrupt existing law. Police will still need to get a warrant before they can discover someone’s past whereabouts, but the Court is likely to place stricter restrictions on what the warrant should say.
Whether those restrictions are strong enough to prevent the government from identifying political opponents and similar groups is unclear, and the question may remain open until the next trial.
