Dick Meyer commenting on the Great Fluid Ban says "... I am mystified by our tolerance for the incompetent, politicized and inefficient charade that is now masquerading as transportation security. Apparently the illusion of security is enough."
Well yeah, Dick, where have you been? The terrorism risk aboard an airplane, even in the "post 9/11 world" is probably less than the chance of having a heart attack from the sheer stress of airline stupidity so actual security is not all that valuable. On the other hand the Great Unwashed have been assured that there is a danger. They don't like to think of a danger they and their protectors can't do anything about. The fact that such a danger is trivial is not the point, it's the degree of control the public have. By inflicting various inconveniences and annoyances on the public the government demonstrates that it is capable of doing someone*. Thus they establish a degree of control and through them the public feel a degree of control. This is what they were after, not genuine security, which in practice they already have to a great extent.
He also opines: "Are we to imagine there aren’t great minds at Homeland Security who spend their time thinking of all the possible ways evil-doers could blow up planes? Of course there are. Are we to imagine they never thought about making bombs with stuff in spray cans? Sure they did. And they surely made rational, practical assessments of the risk."
I don't know why he thinks this. In the wake of 9/11 Condeleesa Rice claimed that nobody foresaw that planes could be used as weapons. However they had. In fact it was the subject of a roleplaying game scenario "Fly to heaven" http://www.rpg.net/news+reviews/reviews/rev_2156.html. So the entire Pentagon could not anticipate an event but 4 guys with a few word processors (which is what Atlas games is really) could. I find it extremely unlikely the security forces have any group tasked with imagining ways the terrorists might strike. They tried something like that with "Seal Team Six" and they embarrassed the high command so much they were disbanded. A contingency planning team can only cause problems for the security services and armed forces forcing to acknowledge the inevitable gaps in security, far to numerous to all plug. The last thing they need is for someone to remove their excuse of ignorance.
* I just noticed that I wrote "someone", where I meant to write "something" but perhaps it's a freudian slip.