National Security Agency whistle-blower Edward Snowden invoked George Orwell and warned of the dangers of unchecked government surveillance Wednesday in a televised Christmas message to the British people that reflected his growing willingness to take a public role in the debate he ignited.

Speaking directly into the camera from Moscow, where he took refuge after leaking vast troves of information on NSA spying, Snowden said government surveillance methods far surpass those described in Orwell's dystopic novel "1984."

"The types of collection in the book — microphones and video cameras, TVs that watch us — are nothing compared to what we have available today. We have sensors in our pockets that track us everywhere we go," he said. "Think about what this means for the privacy of the average person."