You are also asked to take an oath, and that's the oath of service. The oath of service is not to secrecy, but to the Constitution - to protect it against all enemies, foreign and domestic. That's the oath that I kept, that James Clapper and former NSA director Keith Alexander did not. You raise your hand and you take the oath in your class when you are on board. All government officials are made to do it who work for the intelligence agencies - at least, that's where I took the oath.

The power of the presidency is important, but it is not determinative.

Before 2013, if you said the NSA was making records of everybody's phone calls and the [Government Communications Headquarters] was monitoring lawyers and journalists, people raised eyebrows and called you a conspiracy theorist. Those days are over.

Individuals have international duties which transcend the national obligations of obedience. Therefore individual citizens have the duty to violate domestic laws to prevent crimes against peace and humanity from occurring.

No one would argue that it's in the United States' interest to have independent knowledge of the plans and intentions of foreign countries. But we need to think about where to draw the line on these kind of operations so we're not always attacking our allies, the people we trust, the people we need to rely on, and to have them in turn rely on us.

The majority of terrorist attacks that have been disrupted in the United States have been disrupted due to things like the Time Square bomber, who was caught by a hotdog vendor, not a mass surveillance program, not a cyber-espionage campaign.

We've already seen, in practically every country around the world where these issues have been covered, that the general public has recoiled at the ideology behind these programs.