The United States National Security Agency (NSA) appears to have tapped into internal comms links between Google and Yahoo data centres around the world, new documents leaked by Edward Snowden show.
A slide, supplied by Snowden to the Washington Post, contains a sketch describing how the NSA bypasses Secure Sockets Layer (SSL) authentication and encryption measures to intercept data from Google's infrastructure.
With the intra-data centre intercepts in place, the NSA is able to capture information in real-time from Yahoo and Google users. According to the sketch, this includes Gmail, Google Docs and Google Maps data.
The US agency is working with Britain's Government Communications Headquarters (GCHQ) equivalent in intercepting the data centre links as part of Project MUSCULAR which allows the two to copy entire information flows over fibre-optic cables.
Top secret accounting sighted by the Post shows that NSA's acquisitions directorate copies millions of records every day from the networks of Yahoo and Google and stores these in its Fort Meade data warehouse.
Google told the Post that it is troubled by the Government's data interception and said it was unaware it took place. It said it would continue to encrypt data across more of its service and links in response.
The bulk data gathering by the NSA is deemed controversial as it takes in information from US citizens and companies, something that is currently illegal in the United States.