Two questions regarding surveillance
Has NSA surveillance of US citizens prevented terrorist attacks? What harm has come from leaks about the NSA, from Edward Snowden and others?
I'm inclined to answer those questions with "No" and "None", but I'm looking for more information.
Here are the answers to those questions, given by former NSA director Gen. Keith Alexander on the PBS Newshour:
Judy Woodruff: Can you give us an example of a terrorist incident that was prevented because of this kind of work?
Gen. Keith Alexander: Absolutely, 2009, Najibullah Zazi.
Is this so? I have a couple of sources that say that it was mostly FBI and UK intelligence that led to Zazi being found. Is there information that I'm missing about how NSA programs such as PRISM contributed information that was essential to identifying Zazi?
Judy Woodruff: Let me ask you about Edward Snowden. You have argued time and again that he’s done great damage to U.S. national security. How do you quantify that?
Gen. Keith Alexander: Well, it goes back to that terrorist numbers that I gave you.
Here’s what I see. Terrorists and others are adjusting how they operate. We have been very good because we have great tools, great people in the military and the intelligence community helping to defend this country and in law enforcement.
When you take those tools away, it’s analogous to the “Wheel of Fortune,” when you can guess vowels and stuff. And, all of a sudden, they say, well, you can’t guess A and O anymore. You can’t guess some of these, but you have to figure out the puzzle.
And what we’re doing is, we’re taking away some of the tools that our intelligence analysts use to stop terrorist attacks. And I believe, given the fact that terrorist attacks are increasing and that our tools are being publicly revealed, that we put our nation and our allies in greater harm, and I believe that’s why we have said people are going to pay for this with their lives.
This is a screwy answer: Snowden didn't take any tools away. Knowledge of what the NSA is doing only helps the terrorists if they use that information to, say, switch from Yahoo mail to an email service that the NSA isn't shuffling through.
Expanding on my two questions:
Are there cases, other than Najibullah Zazi, of NSA surveillance of US citizens preventing a terrorist attack?
Is there a clear demonstration that, without the NSA, Zazi would not have been identified?
Have leaks by Snowden and others done any harm other than indicating what intelligence capabilities the NSA has?