For years we worried that the likes of Google, Microsoft and Facebook knew too much about us. But when the American intelligence contractor Edward Snowden revealed a list of secret programmes the US and British intelligence services had been working on - it seemed the state had amassed a capability beyond all expectations- intercepting and storing vast amounts of everyday internet traffic.

The power and scale of the intelligence gathering surprised many who concerned about the level of intrusion it represented. But should we be worried and just how much state intelligence gathering are we prepared to accept?

The BBC's Security Correspondent Gordon Corera reports for Newsnight.