Reason contributor and Ohio State political scientist John Mueller and Mark G. Stewart have a must-read piece up at the Chronicle of Higher Education. Read all of "3 Questions about NSA Surveillance." Here's a snippet related to one of two publicly discussed "successes" supposedly based on NSA data, the 2009 arrest of Najibullah Zazi:

Having NSA’s megadata collection may have been helpful, but it seems scarcely to have been required. Actually, it is not clear that even the tip was necessary because the plotters foolishly called attention to themselves by using stolen credit cards to purchase large quantities of potential bomb material.

A set of case studies of the 53 post-9/11 plots by Islamist terrorists to damage targets in the United States suggests this is typical. Where the plots have been disrupted, as in the Zazi case, the task was accomplished by ordinary policing. The NSA programs scarcely come up at all.

When asked on Wednesday if the NSA’s data-gathering programs had been “critical” or “crucial” to disrupting terrorist threats, the agency’s head testified that in “dozens” of instances the database “helped” or was “contributing”—though he did seem to agree with the word “critical” at one point. He has promised to provide a list of those instances. The key issue for evaluating the programs, given their privacy implications, will be to determine not whether the huge database was helpful but whether it was necessary.

Whole thing here.

Check out that set of case studies linked above. It's a great document and source that cuts through a lot of the fog surrounding the issue of terrorism and surveillance.

Read my "Do the Zazi and Headley Arrests Prove the Power of NSA Total Surveillance?" from yesterday.

In 2011, Reason TV interviewed Mueller and Stewart (who teaches at Australia's University of Newcastle) about their book, Terror, Security, & Money: Balancing the Risks, Benefits, and Costs of Homeland Security."