On the heels of last week's phone-tracking revelations, The Washington Post has released a 24-page NSA white paper offering further detail into how the program is managed and used. The program ingests 5 billion records each day into its Hadoop-managed database, but from there, the data can be used for nearly any purpose, from building out networks, ascertaining whether a target is foreign or domestic, or tracking the whereabouts of a known suspect.

One program described in the white paper worked to alert foreign agents if they were being tailed, sifting through the data for location records similar to the records of known agents. If a foreign national was seen in all the same locations as an American agent on a given day, the agency found it safe to assume someone was being tailed. Other uses involved identifying new suspects on the basis of shared movements with a person of interest, or locating phones as they cross international boundaries.