Mr. Snowden getting some air time at TED.

“Some of the most important reporting to be done is yet to come.”

Speaking via a robotic screen from an undisclosed location in Russia, the fugitive promised that there are more revelations to come.

He urged tech firms to protect users by encrypting all web pages.

Web inventor Sir Tim Berners-Lee joined him on stage, describing him as a “hero”.

Ex-NSA (National Security Agency) employee Mr Snowden has leaked thousands of secret documents to newspapers, including the Washington Post and the Guardian, over the past year.

They include revelations about how the NSA gathers vast amounts of information, as well as specific details about its operations.

Mr Snowden told the Ted audience: “Some of the most important reporting to be done is yet to come.”