The 5-4 ruling grants Fourth Amendment protection to what it described as “deeply revealing” data which can be used to create a “detailed chronicle of a person’s physical presence compiled every day, every moment over years.”
“As the Court noted, not only does access to this kind of information allow the government to achieve ‘near perfect surveillance, as if it had attached an ankle monitor to the phone’s user,’ but, because phone companies collect it for every device, the ‘police need not even know in advance whether they want to follow a particular individual, or when’,” said EFF attorneys Andrew Crocker and Jennifer Lynch.
Crucially, the Supreme Court rejected the “Third Party Doctrine”: a legal principle the government had relied on for years to justify its warrantless collection of phone data.
It dates back to the 1970s and asserts that the fact data is collected by a third-party automatically renders it devoid of constitutional protection.
The court ruled that these location technologies are now so advanced they can be used to map in an extremely precise way users’ movements at all times via an “exhaustive chronicle” of data. As such, they represent “a world of difference” from the more limited information collection addressed in previous Supreme Court rulings, it said.
It also explained that this information “is not truly ‘shared’ as one normally understands the term” because device location is recorded automatically “without any affirmative act on the part of the user beyond powering up.”
There are some exceptions to the ruling, including when police are pursuing a fleeing suspect, or when individuals are threatened with immediate harm.
The ruling has emboldened the EFF, which claimed it and other groups would be launching new litigation against other invasive surveillance technologies.