Cell-Phone Location Data is Protected by the Fourth Amendment.

The U.S. Supreme Court has ruled in favor of digital privacy.  In a 5-4 decision on Friday the justices decided that police need warrants to gather phone location data as evidence for trials. The Supreme Court reversed and remanded the Sixth Circuit court's decision.

The Court sent a strong message by recognizing that because of "seismic shifts in digital technology," cell phone tracking has the capability to lay private lives bare to government inspection. The Court also rejected the government’s tired argument that sensitive data held by third parties is automatically devoid of constitutional protection.

In this case, Carpenter v. United States, the government argued that Mr. Carpenter had no reasonable expectation of privacy in his cell phone records, which it obtained without a warrant - while also arguing the location data was incriminating.

The EFF amicus brief argued cell phone records are far too sensitive to obtain without a warrant based on probable cause:

Like the Internet, cell phones are all but essential to modern life, and for years, EFF has fought in courts, legislatures, and public to update the law to protect individuals’ privacy as they move through the world. Cell phones connect to cell towers and antennas hundreds of times a day, creating a non-stop flow of information on everywhere we travel—as the Court wrote, “Sprint Corporation and its competitors are ever alert, and their memory is nearly infallible.”

We are extremely gratified by the Supreme Court’s ruling today. This is a major victory, and we hope it signals the eventual demise of the Third Party Doctrine—that sensitive data held by third parties is automatically devoid of constitutional protection—for good.

Read the decision here: https://www.supremecourt.gov/opinions/17pdf/16-402_h315.pdf