The British Spying agency Government Communications Head Quarters (GCHQ) had reportedly monitored YouTube video views, Facebook 'likes' and Blogger visits in real-time to gather user data, latest leaks by Edward Snowden reveal.
As part of the alleged programme codenamed Squeaky Dolphin, the British spying agency was able to tap the cables transferring global web traffic or use third party to access an immense data stream, as well extract some vital information about specific users.
Citing leaked Snowden documents, NBC News reported that the UK intelligence agency revealed its abilities to the US National Security Agency (NSA) in 2012.
However, Facebook started encrypting its data since then, while Google's YouTube and Blogger services still remain unencrypted.
Facebook spokesman told the BBC: "Network security is an important part of the way we protect user information, which is why we finished moving our site traffic to HTTPS [encryption] by default last year, implemented Perfect Forward Secrecy, and continue to strengthen all aspects of our network."
Both firms have stated that they did not authorise GCHQ to access user information via their services.
Google spokesman said: "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.'
"We do not provide any government, including the UK government, with access to our systems," he added.
"These allegations underscore the urgent need for reform of government surveillance practices."
The latest disclosure also revealed that the agency was able to get a real-time analysis of people's usage of YouTube, Facebook and Blogger through the use of 'Splunk Dashboard'.
GCHQ spokeswoman said: "All of GCHQ's work is carried out in accordance with a strict legal and policy framework which ensures that our activities are authorised, necessary and proportionate, and that there is rigorous oversight, including from the secretary of state, the Interception and Intelligence Services Commissioners and the Parliamentary Intelligence and Security Committee."