Having just gotten back from a grueling 4-leg trip to Hawaii, along with numerous air flights in-between islands, I have to say that security was less on my minds than was crashing from pilot error, mechanical failure, or flying through a thunderstorm (as almost happened out of Oahu). First on my list of concerns was the hassle of getting through security; I had nothing to hide, but I was nervous like a criminal about to be caught for smuggling a pound of blow in my rectum. And it was all about shoes, belts, laptops, SCUBA equipment, and shampoo containers in a Ziploc bag.
The best defenses against terrorism are largely invisible: investigation, intelligence, and emergency response. But even these are less effective at keeping us safe than our social and political policies, both at home and abroad. However, our elected leaders don't think this way: They are far more likely to implement security theater against movie-plot threats.
A "movie-plot threat" is an overly specific attack scenario. Whether it's terrorists with crop dusters, terrorists contaminating the milk supply, or terrorists attacking the Olympics, specific stories affect our emotions more intensely than mere data does.
Stories are what we fear. It's not just hypothetical stories -- terrorists flying planes into buildings, terrorists with explosives strapped to their legs or with bombs in their shoes, and terrorists with guns and bombs waging a co-ordinated attack against a city are even scarier movie-plot threats because they actually happened.