Here's a story (quote is from the second page) where airline security is actually doing harm:
Long lines and chaos snarled evacuees when they tried to
catch flights out from two of Houston's airports. After about 100
federal security screeners failed to report to work Thursday, scores of
passengers missed flights and waited for hours at sparsely monitored
X-ray machines and luggage conveyors. Transportation Security
Administration officials were at a loss for an explanation and
scrambled to send in a team of replacement workers from Cleveland.
This isn't an easy call, but sometimes the smartest thing to do in
an emergency is to suspend security rules. Unfortunately, sometimes the
bad guys count on that.
If I were in charge, I would have let people onto the airplanes. The trade-off makes sense to me. [Schneier on Security]