British writers are among hundreds of the world's leading authors who have condemned the scale of state surveillance in an open letter to the UN.
Signatories including Ian McEwan, Martin Amis and Irvine Welsh have urged the UN to create an international bill of digital rights and called on governments worldwide to support it.
The letter, published in the Guardian, is signed by more than 500 authors from 81 countries including Nobel Prize winners Gunter Grass and Orhan Pamuk.
It comes after a string of disclosures by whistleblower Edward Snowden about the activities of GCHQ and its US counterpart the National Security Agency (NSA).
The letter argues that people have the right to remain unobserved in their communications, after mass surveillance became "common knowledge" in recent months.
"This fundamental human right has been rendered null and void through abuse of technological developments by states and corporations for mass surveillance purposes," it says.
"A person under surveillance is no longer free; a society under surveillance is no longer a democracy. To maintain any validity, our democratic rights must apply in virtual as in real space."
Novelist McEwan, who wrote Atonement and Enduring Love, told the Guardian: "The state, by its nature, always prefers security to liberty. Lately, technology has offered it means it can't resist, means of mass surveillance that Orwell would have been amazed by.
"The process is inexorable - unless it's resisted. Obviously, we need protection from terrorism, but not at any cost."
The latest documents released by Mr Snowden suggest British and US intelligence agencies mounted a concerted drive to infiltrate the world of online games players.
The NSA and GCHQ built "mass collection capabilities" for the Xbox Live console network and were also said to have been tasked with infiltrating "virtual environments" such as World Of Warcraft amid concerns they could be used by terrorists to communicate anonymously online, according to the Guardian.
It comes a day after technology firms including Apple, Google, Microsoft and Facebook wrote to US president Barack Obama demanding sweeping changes to surveillance laws to help preserve the public's trust in the internet.