Russian efforts to interfere in our political system, and the essential question of whether those efforts involved the President Donald Trump campaign, required investigation. In that investigation, it was critical for us( and, before us, the FBI) to obtain full and accurate information. Likewise, it was critical for Congress to obtain accurate information from its witnesses. When a subject lies to investigators, it strikes at the core of the government's efforts to find the truth and hold wrongdoers accountable. It may ultimately impede those efforts.

Robert Mueller

There are only two types of companies: those that have been hacked, and those that will be. Even that is merging into one category: those that have been hacked and will be again.

Robert Mueller

categories type two

No one has ever been able to convince me that optimism is not preferable to pessimism.

Robert Mueller

optimism optimistic able

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

Robert Mueller

cyber threat eclipse

We cannot go up on a wire. We cannot do a search without a judge on the FISA Court approving it and determining that we have met the standard that has been set forth by Congress in order to utilize these techniques.

Robert Mueller

wire judging order

I think around the world, our agents are the best collectors of information you'll find.

Robert Mueller

agents world thinking

So without getting into the specifics, I can tell you that to the extent that investigation is a relatively important investigation and meaningful, the president would have been periodically briefed.

Robert Mueller

important president meaningful

I asked a Burmese why women, after centuries of following their men, now walk ahead. He said there were many unexploded land mines since the war.

Robert Mueller

women land war

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.

Robert Mueller

agents always-trying mean

Leaking of classified material is a concern.

Robert Mueller

concern materials

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

Robert Mueller

warrants purpose

But we had - I think if you look at law enforcement 10 years ago, if you look at the challenges, the FBI was focused excessively on what was happening in the United States.

Robert Mueller

law years thinking

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.

Robert Mueller

differences mean facts

In the last 10 years, in narcotics task forces, in a number of violent crime task forces, we've worked very closely together with state and local law enforcement.

Robert Mueller

law numbers years

And so every one of us in the FBI, I don't care if it's a file clerk someplace or an agent there or a computer specialist, understands that our main mission is to protect the public from another September 11, another terrorist attack.

Robert Mueller

agents september-11 clerks

People talk about the Patriot Act that was passed immediately in the wake of September 11. What the Patriot Act did was break down the walls between the various agencies.

Robert Mueller

wall agency people

What we bring to the table is not only our 56 field offices in the United States and our number of resident agencies, but also we have 45 legal attaches overseas.

Robert Mueller

agency numbers america

There'll be differences of opinion in just about every intelligence analysis that you make.

Robert Mueller

analysis opinion differences

In the context of September 11, there were so many that lost their lives that - how do you single out one person? There were so many acts of heroism that day from so many people, whether it be firemen and police officers in New York and our agents also.

Robert Mueller

police new-york people

And from the moment that we realized it was a terrorist attack, there isn't an agent or a support person in the FBI that wasn't committed to bringing to justice those who were responsible for this.

Robert Mueller

agents support justice

I didn't know the organization, but the one thing you can say about the FBI, it's tremendously professional.

Robert Mueller

fbi organization knows