Snowden documents leaked to Der Spiegel in December 2013 describe a different type of NSA program from the sort that is usually publicized.
Rather than revealing software developed by the agency in order to access computers, these revelations describe a secret elite hacking unit, dubbed Tailored Access Operations, or TAO.
FRONTLINE asked security expert Bruce Schneier to break down its capabilities.
You can watch our full report on NSA surveillance, “United States of Secrets,” online anytime: https://to.pbs.org/1eDFGyQ