Coming up on Nightline

W A S H I N G T O N, July 10 -- When I was brand new in local television, I had to call the CIA for something, I don't remember what. They were listed in the phone book in San Francisco. I called the number, and the person on the other end answered by reciting the number I had dialed. I asked if I had reached the CIA. She said she couldn't tell me. I said that the number was listed as the CIA. She said she couldn't comment. I hung up. True story.

We actually are able to cover the CIA occasionally. We did a series of broadcasts on their predictions for the coming years. But the National Security Agency, the NSA, is different. They rely not on human intelligence, not on spies, but on technology. On listening. Phone calls, emails, fax transmissions, all fair game. With satellites, listening posts, spy ships, planes, you name it, they can listen to just about anything. One listening post can reportedly pick up about two million phone calls and emails an hour.

Now one of the problems is going through all that. How can all of that information be processed? How do you make sure you're not missing the phone call from Osama bin Laden in the midst of all of that traffic? And some in the intelligence community have criticized the NSA for missing crucial warnings of terrorist attacks. And how can they stay ahead of the rapidly advancing technology?

But for most Americans, mention the NSA and another issue comes up. The official position is that the NSA does not eavesdrop on Americans without a court order. This follows after the abuses of the 1970's, when the Nixon White House ordered the NSA to spy on the anti-war movement. But that won't convince a lot of people who just don't believe it. So the NSA is being hit from both sides, some say they're not listening enough, others say they're listening too much. The truth?

Chris Bury will have a rare interview with the director of the NSA tonight. We hope you'll join us.

Leroy Sievers is the executive producer of Nightline.