"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."