[WashingtonPost] NSA infiltrates links to Yahoo, Google data centers worldwide, Snowden documents say
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. [...]
It is not clear how much data from Americans is collected and how much of that is retained. One weekly report on MUSCULAR says the British operators of the site allow the NSA to contribute 100,000 “selectors,” or search terms. That is more than twice the number in use in the PRISM program, but even 100,000 cannot easily account for the millions of records that are said to be sent to Fort Meade each day.
In 2011, when the FISC learned that the NSA was using similar methods to collect and analyze data streams — on a much smaller scale — from cables on U.S. territory, Judge John D. Bates ruled that the program was illegal under FISA and inconsistent with the requirements of the Fourth Amendment.