EDITORIAL

Protect our metadata

Law enforcement officials are accused of obtaining location data from an accused criminal's cell phone to link him to crimes. The case has now gone before the Supreme Court.

A Supreme Court case that could redefine privacy law in the 21st century began with a robbery in Detroit.

The perpetrators held up eight more stores in Michigan and Ohio over a three-month period. In April, 2011, law enforcement apprehended four suspects, one of whom confessed to the crimes and gave the FBI his cell phone number, as well as those of his cohorts.

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Police then obtained 127 days’ worth of records from cellphone companies showing the movements of the man who had organized most of the robberies, Timothy Carpenter.

The data placed Mr. Carpenter’s phone at 12,898 locations, some of them nearby the stores when the robberies took place. Prosecutors used the information to reach a conviction, which has since been appealed all the way up the nation’s highest court.

Mr. Carpenter’s defense argues that without a warrant, this collection of tracking data by law enforcement constitutes an unreasonable search and seizure, which is prohibited under the Fourth Amendment.

Collecting the metadata of a phone conversation — the who, when, where, and how long of the exchange, but never the what — is not considered an unreasonable search under U.S. law at present.

The legal principle behind this stance is known as the “third-party records doctrine,” which asserts, essentially, that a person surrenders his constitutional privacy right over information that he turns over to a third-party. Pre-internet and pre-smart phone, this principle was uncontroversial.

But most people today share information with third parties from the moment they leave bed in the morning until the moment they go to bed at night. From his cell site location data, prosecutors could tell whether Mr. Carpenter had slept at home or elsewhere, and whether he attended his usual church on Sunday mornings.

People today are also constantly sharing information with third parties via the Internet. Even though law enforcement can only access the metadata of your browsing activity — like they can only access the metadata of your phone usage — unless granted a warrant, this information can provide alarmingly fulsome insights into citizens’ private lives. For instance, how often a person opens a dating app or visits one website or another. Before this shift, police would have needed a search warrant to learn these kinds of details about a suspect.

The extent of what can be known about a person through his metadata is such that a defeat for Mr. Carpenter would even have broad implications for First Amendment speech rights. For example, cell site location information “can reveal the stories a journalist is working on before they are published, where a journalist went to gather information for those stories, and the identity of a journalist’s sources,” as the Reporters Committee for Freedom of the Press observes in its brief in the Carpenter case.

In 2014, the Supreme Court ruled that police cannot break into a criminal suspect’s cell phone without a search warrant. The same First and Fourth Amendment principles apply here.