« The information published this weekend is another revelation courtesy of leaker Edward Snowden. The 50,000-figure comes from a 2012 presentation slide explaining how the NSA acquired information worldwide. It described an initiative called « Computer Network Exploitation » (CNE), which NRC reports as « the secret infiltration of computer systems achieved by installing malware. » » (via Report: NSA-planted malware spans five continents, 50,000 computer networks | Ars Technica)