What we do is we combine information collected from any lawful source in a single FBI database so we don't miss a dot when we're conducting investigations in the United States. What we make sure of, though, is nobody gets to see FISA information of any kind unless they've had the appropriate training and have the appropriate oversight.

In their minds, the murderers and accomplices of Germany, and Poland, and Hungary, and so many, many other places didn't do something evil. They convinced themselves it was the right thing to do, the thing they had to do. That's what people do. And that should truly frighten us.

Secretary Hillary Clinton used several different servers and administrators of those servers during her four years at the State Department. She also used numerous mobile devices to send and to read email on that personal domain.

Only a very small number of the e-mails containing classified information bore markings indicating the presence of classified information. But even if information is not marked 'classified' in an e-mail, participants who know or should know that the subject matter is classified are still obligated to protect it.

I'm in the business where I can't ever say there's no risk associated with someone.

Our process inside the United States government has gotten much better at making sure we touch all possible source of information about a refugee. The interview process has gotten more robust, so we've gotten our act together in that respect. The challenge remains, especially with respect to folks coming from Syria, we're unlikely to have anything in our holdings. That is, with people coming from Iraq, the United States government was there for a very long period of time. We had biometrics, we had source information. We're unlikely to have that kind of picture about someone coming from Syria.

I believe that Americans should be deeply skeptical of government power. You cannot trust people in power. The founders knew that. That's why they divided power among three branches, to set interest against interest.