According to the latest leaks from former National Security Agency contractor-turned-whistle-blower Edward Snowden, the NSA gathers about 5 billion cell phone records around the world every single day, and nearly 2 trillion each year. The programs, known collectively as "Co-Traveler," allow the NSA to track the locations of any cell phone in the world, retrace its movements, and map user relationships in ways that surpass many of the secret NSA programs previously leaked by Snowden.

The NSA maintains that Co-Travler, like others leaked by Snowden, are legal and only intended to gather intelligence about national security targets. The NSA said it is not interested in everyone’s data and does not intentionally collect U.S. data in bulk. The NSA also insists that the Fourth Amendment, which prohibits unreasonable search and seizure, does not protect cell phone data.

But the nature of the program requires that the NSA casts as wide a net as possible and analyze the location information of billions of innocent cell phones. The NSA calls this “incidental” data collection, which makes the process legal because it is not a deliberate collection of data.

Here is how Co-Traveler works:

  1. 1. NSA Utilizes Vast Cell Tower Coverage

To send and receive phone calls and messages, cell phones emit mobile signals to nearby cell towers. Even if location services like GPS are turned off, these signals reveal the physical location of the phone. The majority of world is now covered with cell towers, giving the NSA the ability to find a cell phone almost anywhere in the world. According to Snowden’s documents, the communication companies give the NSA this data, though the companies involved were given code names.

2. How NSA Gets Location Data

When the device connects to the network via the cell tower, the telephone company registers the connection in order to connect the phone and to bill the user. This registration includes the city and country of the cell phone as well as its position relative to the cell tower. The NSA can also triangulate the phone’s position from multiple towers to get even more accurate location data.

The NSA can locate devices using Wi-Fi down to a city block, and devices using GPS can be located within a radius of 100-meters.

3. Co-Traveler Analytics To Find Associates

Once the NSA has the location data, as well as other information like the date and time it connects with a mobile network, the NSA uses it to determine its proximity to an NSA target within a one-hour timeframe. As a target passes by multiple cell towers, the NSA will look for others following a similar path and identify these users as “co-travelers.” Once an individual is determined to be a co-traveler, the NSA continues to collect and monitor their location even if the individual is not determined to be a target.

4. Vast Database Of Location Data

The NSA cannot know in advance which location data it will end up needing, so it stores all of it in a massive database as large as 27 terabytes. According to the Washington Post, the NSA is collecting so much data that it's outpacing its own ability to process and store it.

This means that the NSA is collecting data on people going to business meetings, visits to the hospital, hotel rooms and private homes and storing it in a massive database. Perhaps most troubling is that the only way to avoid the detection is to stop using cell phones, Wi-Fi and GPS altogether.

To learn more, read the original articel at the Washington Post, and check out this excellent infographic that breaks down Co-Traveler. 

What do you think of the latest Snowden leak? Let us know in the comments section.