Whistleblower: US surveillance 'disturbing'
10 June 2013 Last updated at 11:33 BST
The US Department of Justice has confirmed it is in the initial stages of a criminal investigation into Edward Snowden's unauthorised disclosure of secret information.
In light of this, the BBC spoke with Thomas Drake, who was a senior executive of the National Security Agency until he was accused under the Espionage Act for whistle-blowing in 2010.
Mr Drake explained how Snowden's revelations demonstrate the development of the "surveillance state".
He said: "I blew the whistle originally on the secret surveillance programme within the system. This simply shows the incredible expansion of the surveillance state on a scale that no-one ever imagined we would be dealing with today."
He described the US as a "Leviathan security state" and went on to say: "What's most disturbing about this is the pretence of counter-terrorism or the pretence of the war on terror or the pretence of even proper cause is not even in this. It's 'we just need the data'."
Mr Drake spoke with the BBC's Adnan Nawaz.