Thanks in part to the documents released by Edward Snowden, the true scale of the National Security Agency's scope and power is coming to light. Besides spending billions to ingest and analyze the worlds' electronic communications, the NSA has set out to dominate a new battlefield, cyberspace. Nova examines the science and technology behind cyber warfare and asks if we are already in the midst of a deadly new arms race.

Originally broadcast on PBS stations on October 14, 2015 as an episode of the WGBH television series, NOVA. Title from web page.