Not only is the U.S. government gathering information from tech companies on global Internet traffic -- according to new reports, the NSA is also siphoning off data from underseas cables that criss-cross the world.

The Washington Post on Wednesday published a classified NSA slide that provided side-by-side guidance on the two surveillance programs.

"You Should Use Both," the slide said, in an apparent message to NSA personnel.

At the bottom was a description of "PRISM," the previously reported program that collects data from tech companies. At the top was a blurb on "Upstream," which it described as "collection of communications on fiber cables and infrastructure as data flows past."

The Post article suggested the latter was part of an effort to tap into the fiber-optic cables that contain gobs of voice and Internet data.

The slide contains a rough map of North America, showing the underseas cables fanning out from the West and East coasts of the United States, to the rest of the world.

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