(Slide from NSA MYSTIC presentation)

Published every weekday, the Switchboard highlights five tech policy stories you need to read.

NSA recorded ‘every single’ call in one country. "The National Security Agency has built a surveillance system capable of recording '100 percent' of a foreign country’s telephone calls, enabling the agency to rewind and review conversations as long as a month after they take place," reports Barton Gellman and Ashkan Soltani for The Washington Post. The voice interception program is called MYSTIC.

Edward Snowden: Here's how we take back the Internet. In a TED talk on Tuesday, former NSA contractor Edward Snowden outlaid his vision for a more secure Internet -- echoing many of the same themes as his recent SXSW livestreamed panel.

Why MH370 could still talk to satellites after its other comms went dark. "It's the latest mystery in the hunt for Malaysia Airlines Flight 370: Was a key communications system on board the plane disabled before or after the co-pilot calmly bid air traffic controllers goodnight?" writes the Switch's Brian Fung. "Malaysian authorities said on Sunday that the system, known as ACARS, was disabled before that final radio transmission, which would seem to bolster theories that the pilots were somehow involved in the plane's disappearance. But further digging provides some reason to doubt that account."

10,000 Linux servers hit by malware serving tsunami of spam and exploits. "Researchers have documented an ongoing criminal operation infecting more than 10,000 Unix and Linux servers with malware that sends spam and redirects end users to malicious Web pages," reports Ars Technica's Dan Goodin. "Windigo, as the attack campaign has been dubbed, has been active since 2011 and has compromised systems belonging to the Linux Foundation's kernel.org and the developers of the cPanel Web hosting control panel, according to a detailed report published Tuesday by researchers from antivirus provider Eset." Windingo infected more than 25,000 servers to send more than 35 million spam messages per day over 36 months. It also exposed Windows-based online visitors to malware attacks and replaced regular banner ads with ads for porn services.

Facebook creates software that matches faces almost as well as you do. "Asked whether two unfamiliar photos of faces show the same person, a human being will get it right 97.53 percent of the time," writes Tom Simonite at the MIT Technology Review. But Facebook is catching up with humans. "New software developed by researchers at Facebook can score 97.25 percent on the same challenge, regardless of variations in lighting or whether the person in the picture is directly facing the camera."