TSA Claims 'National Security' to Avoid Answering Question on Success Rate

I do not really understand how giving out a number of successfully prevented terrorist attacks has a legitimate National Security component. If they were asked for specific details on how they figured it out (assuming they had), that could have some implications. While it may be unfair to say refusing the answer the question means they have not caught any, it is likely that the number is embarrassingly small given the resources dedicated and the burden/impact on travelers.

http://www.techdirt.com/articles/20101119/18284511954/whether-not-tsa-has-ever-caught-terrorist-is-apparently-state-secret.shtml

"We asked recently if there was any evidence, ever, that the TSA's security procedures prevented an attack on an airplane. Last week the TSA claimed, without any details, that its procedures had stopped 130 "prohibited, illegal or dangerous items" from getting on airplanes in the last year. But it provides no details. And, in a day when a bottle of water and nail clippers are considered "prohibited," it's difficult to judge if this actually means anything.

Over at Slate, Juliet Lapidos tries to dig into the question, but the TSA won't point out a single specific case claiming it's a "national security" issue. Huh? Actually telling us whether or not the naked scans and crotch grabs catch anyone is a state secret? That seems likely to mean that the answer is, no, they have not caught anyone or stopped any attempted attack, and they're just too embarrassed to say so. In fact, Lapidos points out that, in years past, the TSA has publicly announced when it "caught" someone -- as in the one time, nearly three years ago, it found a guy who had enough materials in his (checked) suitcase to make a pipe-bomb. Of course, there wasn't an actual pipe bomb in the suitcase, so it wasn't going to blow up the plane or anything."