Leaked confidential documents suggest the NSA has been secretly harvesting data from Google and Yahoo networks, giving the agency access to hundreds of millions of emails accounts.
Operating under the name Project Muscular, the NSA is believeed to have been using an unnamed telecoms provider to gain access to relevant cables/switches that Google and Yahoo use to transfer data.
Data of US and foreign civilians has been intercepted at point outside of the US, documents obtained by former NSA contractor-turned whistle blower Edward Snowden reveal.
We are outraged at the lengths to which the government seems to have gone to intercept data from our private fiber networks, and it underscores the need for urgent reform.
Accounting data from 9 January 2013 shows the NSA processed 181,280,466 new records in a 30-day period. The documents suggest the NSA was not only gathering metadata but snooping on the text, audio and video content within emails.
Google expressed outrage at these latest developments, re-iterating that it does not provide the US government with access to its systems.
"We have long been concerned about the possibility of this kind of snooping, which is why we have continued to extend encryption across more and more Google services and links, especially the links in the slide," said David Drummond, Google's chief legal officer.
"We are outraged at the lengths to which the government seems to have gone to intercept data from our private fiber networks, and it underscores the need for urgent reform."
Meanwhile, Yahoo appeared to claim that its data centers have not been compromised.
"We have strict controls in place to protect the security of our data centers, and we have not given access to our data centers to the NSA or to any other government agency," the firm said in a statement.
The NSA denied that it collects vast quantities of data from US citizens in this manner - claiming that it is focused on gathering foreign intelligence.
"NSA applies Attorney General-approved processes to protect the privacy of US persons - minimising the likelihood of their information in our targeting, collection, processing, exploitation, retention, and dissemination," the agency said in response to the allegations.
"[We're] focused on discovering and developing intelligence about valid foreign intelligence targets only."
