Former US National Security Agency contractor has addressed British public through a televised Christmas message, warning of the dangers posed by a loss of privacy.
Edward Snowden, who revealed details of electronic surveillance by American and British spy services, appeared in a two-minute video recorded in Moscow and broadcast by Britain's Channel 4 television station on Wednesday.
The US whistleblower said that modern surveillance was more invasive than any envisioned in the novel "1984" by George Orwell, and warned that children today would grow up without knowing what it means to have an unrecorded or private moment.
Together we can find a better balance, end mass surveillance and remind the government that if it really wants to know how we feel, asking is always cheaper than spying,
"We have sensors in our pockets that track us everywhere we go. Think about what this means for the privacy of the average person," Snowden said.
The challenge now, he believes, is to stress the importance of privacy and urge an end to mass government surveillance.
"The conversation occurring today will determine the amount of trust we can place both in the technology that surrounds us and the government that regulates it," he said.
"Together we can find a better balance, end mass surveillance and remind the government that if it really wants to know how we feel, asking is always cheaper than spying."
Keeping a mostly low-profile since getting asylum by Moscow, Snowden has suddenly resurfaced in the media, saying he is confident his personal mission is already accomplished and he has already won after leaking NSA secrets.
Snowden left his NSA post in Hawaii in May and went public with his first revelations from Hong Kong a few weeks later.
In June, he left for Russia and stayed at Moscow's Sheremetyevo airport for nearly six weeks until the Kremlin granted him temporary one-year asylum.
The US has revoked his passport and demanded he be sent home to face charges for stealing secrets.
Channel 4 every year produces a Christmas message, an alternative to the one delivered by Queen Elizabeth II to the nation, and has used it to give a platform to people as diverse as Iran's then-President Mahmoud Ahmedinejad in 2008, and fictional characters including Ali G and Marge Simpson in 1999 and 2004, respectively.