The Washington Post reports: The National Security Agency has secretly broken into the main communications links that connect Yahoo and Google data centers around the world, according to documents obtained from former NSA contractor Edward Snowden and interviews with knowledgeable officials.

By tapping those links, the agency has positioned itself to collect at will from among hundreds of millions of user accounts, many of them belonging to Americans. The NSA does not keep everything it collects, but it keeps a lot.

According to a top secret accounting dated Jan. 9, 2013, NSA’s acquisitions directorate sends millions of records every day from Yahoo and Google internal networks to data warehouses at the agency’s Fort Meade headquarters. In the preceding 30 days, the report said, field collectors had processed and sent back 181,280,466 new records — ranging from “metadata,” which would indicate who sent or received e-mails and when, to content such as text, audio and video.

The NSA’s principal tool to exploit the data links is a project called MUSCULAR, operated jointly with the agency’s British counterpart, GCHQ. From undisclosed interception points, the NSA and GCHQ are copying entire data flows across fiber-optic cables that carry information between the data centers of the Silicon Valley giants.

The infiltration is especially striking because the NSA, under a separate program known as PRISM, has front-door access to Google and Yahoo user accounts through a court-approved process.

The MUSCULAR project appears to be an unusually aggressive use of NSA tradecraft against flagship American companies. The agency is built for high-tech spying, with a wide range of digital tools, but it has not been known to use them routinely against U.S. companies. [Continue reading…]