Snowden leaks: Levison fearful for future of 'freedom'
31 January 2014 Last updated at 22:05 GMT
Ladar Levison, the founder of private email service Lavabit, has told BBC Click's Jen Copestake he is concerned the US government is "slowly gaining unfettered access to the entire world's communications."
"I do not trust a government that operates in secret," he said, adding: "There may come a day when the United States is no longer associated with the word 'freedom' in people's minds."
Lavabit was used by former US National Security Agency (NSA) contractor, Edward Snowden, who leaked to the media details of extensive internet and phone surveillance by American intelligence.
The company is in court appealing against a US government order to hand over its encryption keys.
Commentators say the case could become a landmark one for internet privacy.