Supreme Court rules police need a search warrant to track your iPhone


Your wireless service provider always knows where your iPhone is, but police can no longer access that data without a search warrant.

The U.S. Supreme Court just handed down a victory for privacy advocates: police can no longer access mobile phone tracking data without a warrant.  

Wireless providers know which of its cell towers each of their customers is connected to, giving it a basic idea of where all of them are. Law enforcement agencies used to be able to obtain this data without permission from a judge.

The cell phone location data wasn’t protected by privacy laws because police weren’t getting it from the individuals, it was data that belonged to the wireless providers.

Phone location data now protected

This morning, the Supreme Court ruled that the U.S. Constitution protects this type of data. Specifically, the Fourth Amendment prohibits unreasonable searches and seizures.

It was a 5-4 decision, with Chief Justice John Roberts joining the court’s four progressive justices in agreement. “A cell phone faithfully follows its owner beyond public thoroughfares and into private residences, doctor’s offices, political headquarters, and other potentially revealing locales,” Roberts wrote in the decision.

All the remaining conservative judges disagreed.

Apple, Google, Facebook, Microsoft and several other tech companies concurred with the majority decision, though. They’d earlier filed a “friend of the court” brief (PDF) that stated “No constitutional doctrine should presume that consumers assume the risk of warrantless government surveillance simply by using technologies that are beneficial and increasingly integrated into modern life.”

Reasonable grounds vs. probable cause

After this decision, law enforcement agencies can still get phone location data from wireless providers, but they need a search warrant to obtain it. But getting a warrant requires probable cause, a term meaning “information sufficient to warrant a prudent person’s belief … that evidence of a crime or contraband would be found in a search,” according to The Oxford Companion to American Law.

Previously, police only needed reasonable grounds to think that the data will help a criminal investigation. That’s why it’s become so common, with police making over 100,000 requests for phone location data in 2016.

Chief Justice Roberts cited the huge number of these requests as reason for the Supreme Court’s decision today. “This newfound tracking capacity runs against everyone.”

The Supreme Court has made, or will make soon, a number of decisions related to Apple and the tech industry. It recently ruled that states can require internet retailers to collect sales taxes. And it will decide next year if app developers can sue Apple for holding an illegal monopoly on distributing iOS software.


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