That's the interesting premise of this article in Wired. Security theater, where there's more of a show than a real security measure (think taking your shoes off at the airport and the goo rules), might have its uses:
We make smart security trade-offs -- and by this I mean trade-offs for genuine security -- when our feeling of security closely matches the reality. When the two are out of alignment, we get security wrong. Security theater is no substitute for security reality, but, used correctly, security theater can be a way of raising our feeling of security so that it more closely matches the reality of security. It makes us feel more secure handing our babies off to doctors and nurses, buying over-the-counter medicines and flying on airplanes -- closer to how secure we should feel if we had all the facts and did the math correctly.
Which is all pretty valid. I was about to say, "yeah, but" until I read the next paragraph:
Of course, too much security theater and our feeling of security becomes greater than the reality, which is also bad. And others -- politicians, corporations and so on -- can use security theater to make us feel more secure without doing the hard work of actually making us secure. That's the usual way security theater is used, and why I so often malign it.
If our fears really are all out of proportion to reality, as is likely the case with the air situation, maybe the theater is enough to make some people calm down to the level of threat that really exists. But to me it's so obviously theater that it just seems like a big waste of time and money. My comfort level would be much raised if we had, say, cargo screening instead of toothpaste in plastic baggies.