In the future, the cyber threat will equal or even eclipse the terrorist threat.

All I'm going to tell you is investigations, whether it be this and others, where you have partial facts, analysts, agents are always trying to interpret what those facts mean, extrapolate from them what they mean.

I was in my office when - on 9/11. I think I had a number of meetings scheduled. I was just getting to know the bureau. And somebody walked in and said the first plane had - or a plane had struck the World Trade Center, one of the towers.

The 19 hijackers that came over here to commit the attack on Sept. 11, there were those that were at the bottom of the line. There were those who were the principal conspirators. There were those who were the pilot. Everybody has a role.

I would say in just about every investigation we have, there will be differences of opinion, where you have partial facts, as to what those facts mean.

But since September 11, we have made every effort to try to work closely with state and local law enforcement.

So there is a foreign intelligence purpose for every one of our FISA warrants.