Almost five billion records revealing the location of mobile phones around the world are collected by the US National Security Agency every day.
Data collected by the NSA provides the US with the ability to pinpoint hundreds of millions of phones and their users daily, it was reported.
Moreover, the records allow US intelligence agents to establish not just the movements of individuals but to monitor who else they communicate with.
The scale of the monitoring project was revealed by officials speaking to the Washington Post, combined with documents made public by Edward Snowden, who worked for the National Security Agency before he leaked the secret files.
“We are getting vast volumes,” an unnamed official told the newspaper, by tapping into cables that connect mobile networks.
Chris Soghoian, principal technologist at the American Civil Liberties Union, said the data enables US intelligence to find the location of suspects even if their communications are encrypted.
“One of the key components of location data, and why it’s so sensitive, is that the laws of physics don’t let you keep it private,” he said. “The only way to hide your location is to disconnect from our modern communication system and live in a cave.”
The NSA uses powerful analytical tools known as CO-TRAVELER to trawl through the data to identify who their suspects are talking to and to study their patterns of movement.
So much data has been collected, it is believed, that the NSA is storing the equivalent of more than twice the quantity of text being held by the Library of Congress’s print collection.