Washington (CNN)For years, federal Judge Reggie Walton served on the secretive Foreign Intelligence Surveillance Court, which repeatedly approved the U.S. government's requests to collect telephone metadata on millions of Americans.
Leading the secret FISA court: Q&A with Judge Reggie Walton
Walton also served as the FISA court's presiding judge. And he was tapped to lead the court just months before former NSA contractor Edward Snowden unleashed an era of intense public scrutiny and attention toward the court.
He left the FISA court last year after a 7-year stint.
Here is a lightly edited transcript of CNN's interview with Walton, the court's only former presiding judge who served during and after the Snowden leaks.
CNN: How many cases did you preside over while you were on the FISA court? And how demanding was the job?
Reggie Walton: I can't really calculate how many cases it was. Over the course of a week you would probably hear 40 cases.
It's very demanding. Information that is submitted by the government is 50, 60, 70 pages or more. And obviously you have to read more information to familiarize yourself with what the government is requesting.
CNN: What was your top concern as the FISA Court's chief judge? National security or civil liberties?
Walton: I think it's a combination of both, which makes the job very demanding.
CNN: Why do you believe the bulk data collection that you approved is so crucial to national security?
Walton: Once a potential terrorist is identified, you have to be in a position to quickly assess who that individual has been in contact with. And if we had been able to do that prior to 9/11, maybe 9/11 would not have happened.
CNN: Reform supporters point to several reviews of NSA surveillance that haven't found any instance in which a terror plot was thwarted because of the bulk data collection program. What do you say to that?
Walton: Well I don't know if that's necessarily accurate.
The political branches have to decide exactly what they want because obviously with freedom and liberty comes a price and with security comes a price. And that's the balance that the political branches need to make.
CNN: So you were basing your decisions on existing law?
Walton: That's correct. As a judge I have an obligation to apply the law as I believe the legislature has enacted it. And it was based upon that assessment that approvals were given.
CNN: Section 215 says specifically that the government can request a secret warrant "tangible things" that would be "relevant" to an ongoing investigation. How did you come to determine that Section 215 could be used to collect data on millions of Americans based on that relevancy requirement?
Walton: Well the 215 program was in operation before I came on the court.
CNN: So you were following FISA court precedent?
Walton: Well I mean there have been several opinions that were written by my former colleagues on the court and I did not take exception with those decisions. I did not disagree with their evaluations.
CNN: Do you think it's appropriate for the government to hold the telephony metadata of millions of Americans?
Walton: Well it's been approved by Congress because they reauthorized the Patriot Act in 2011,the program had been in existence and I know that the Justice Department had made Congress aware of the fact that these programs were being conducted.
[Editor's note: The Justice Department informed all members of Congress in a 2011 classified memo of the bulk data collection program.]
CNN: Why in your opinion should the government be able to continue to hold that metadata?
Walton: It's not my prerogative. It's the political branches that have to make that decision. Obviously if they want to terminate it that's their prerogative within our constitutional system.
There may be a price to pay at some point down the line, but if the political branches are willing to pay that price that's their prerogative.
CNN: Your were the chief judge when the FISA court approved the order in 2013 for the NSA to collect bulk data from Verizon. Could you take us into that decision? What kind of details could you provide to Americans about how that decision came about?
Walton: I don't know if that's been declassified or not so I don't feel comfortable commenting on that at all.
CNN: You found in 2009 that the NSA hadn't been following the rules of data collection for two and a half years.
Walton: I've been out of the court for about a year and memories fade, so I don't want to comment specifically on any particular action or document.
I can only say generally that I and my colleagues did vigorously scrutinize what the government was requesting. And if we felt there were any problems with regards to that collection, we took aggressive action to ensure that that over-collection did not continue and that information that was inappropriately acquired was purged.
CNN: Do you think that raises questions of how much you can trust the NSA with storing -- but not looking at -- the data of millions of Americans?
Walton: Not at all.
I had no reason to believe during the seven years I served on the court that anybody at NSA nefariously did anything in reference to data that they were acquiring.
Sometimes in the attempt to try and keep the country safe, mistakes occur. But I never found anything that they did was malicious. And I also found them to be very forthright. Whenever they realized that something had gone astray, they brought that information to us.
CNN: In your opinion, what is the biggest misperception the public has about the FISA court and NSA bulk data collection?
Walton: I think one is the misperception that the FISA court was just a rubber stamp.
After the Edward Snowden leaks, the press was reporting information provided by the Justice Department about how many applications had been approved by the court. It did not sound like reality to me.
I started to have us internally collect our own statistics to find out exactly what was going on. And in a document I produced to congress we showed that over a three-or four-month period that we were either rejecting or significantly changing what was being requested of us in about 24% of the cases.
The Justice Department was only reporting those rejections when they submitted a final draft that was rejected. They weren't reporting the fact that initially when an application comes in it's reviewed by one of the staff attorneys and if the staff attorneys have an issue with it, then that doesn't go forward. They weren't counting that as a rejection.
If the Justice Department was seeking 10 authorizations but the court only approved two. They weren't reporting that eight had been denied. Or once it got to the judge and the judge had issues or thought there wasn't sufficient information -- if it was not a final application -- then that was not reported.
CNN: What recommendations would you suggest to reform the FISA court or the laws governing bulk data collection?
Walton: I don't think that's the role of a judge. I don't think ethically it's appropriate for me to opine on that.
CNN: There's a lot of discussion about adding a civil liberties advocate or someone playing an adversarial role in the FISA court. Is that something you feel like you would have liked to have when you were on the court?
Walton: It conceivably could have been helpful in a limited number of cases, but the difficulty obviously is that the information that's being presented to the court is extremely highly classified.
In my experience the five lawyers that I worked with were extremely qualified. I always felt that they gave me an objective assessment of the pros and cons of what the government was seeking. So I felt that I was getting the information that I would get from an independent party in any event.
CNN: Would they present specific arguments tied to civil liberties concerns?
Walton: Sure. That was something that was frequently raised.
CNN: Do you appreciate or understand some of the concerns that civil liberties advocates raise?
Walton: I understand the concern when proceedings are conducted in private. I fully appreciate that. But I don't know how you effectively conduct mass security electronic surveillance if it's not done in private.
If you're going to tell the world what you're doing then you might as well not do it.
I think a lot of people don't appreciate the significant threats that we face as a nation. I got up every day fearful that something catastrophic like another 9/11 would happen.
CNN: What else do you think Americans should know?
Walton: I feel very confident that the judges who serve on the FISA court are extremely dedicated individuals who appreciate the importance of civil liberties, but also the very important need to protect people from having to make a decision as they did at on 9/11 as to whether they wanted to burn to death or whether they wanted to jump to their death.
That's a very difficult balance about protecting the nation on one hand but on the other hand not giving them the prerogative to be able to violate the civil liberties that are the hallmark of our country.
There were times when myself and I'm sure my colleagues had to deny things that the government wanted and it wasn't easy to do that. Even though you did that because it was your duty, you were always concerned that, 'Well did I deny them something that would conceivably cause the country to be at greater risk?'
But that's the hard call that judges have to make.
CNN: Are there any decisions you made that you regret?
Walton: I can't think of any specific decision.
CNN: Are you confident that you struck the appropriate balance between civil liberties and national security?
Walton: I believe so. I don't know of any situation where somebody has been able to show that NSA or any other national security agency intentionally violated the civil liberties of American citizens.