Actually, given that their "intelligence" led to the horrific catastrophe known as the Iraq War (remember the imminent threat of Saddam's WMDs?) the US intelligence services and the US government are under every obligation to publicly prove everything.

Clapper is a proven liar who has repeatedly lied to the Senate and the Congress under oath.  Any sensible person knows not to take the word of a baldfaced liar on faith alone.  Moreover, he's an Obama appointee doing the Democrats dirty work for them. So, we can easily disregard anything Clapper has to mumble on the subject.

What you forget Thomas, is that the government and its agencies (including the intelligence services) work for the people, and not the other way around.