On a separate note, the TSA really pisses me off. Consider that UPS saves millions by not taking left turns. Removing or adding very small inefficiencies at a very large scale has tremendous cost implications. I don't think these security lines add much security and I think they do that task at a much higher cost than most people think.
Have we? Maybe US passengers have been taught that better than elsewhere, but we don't really know due to the lack of hijackings to test that theory.
And internationally, of about a dozen hijackings post 9/11 only two I think have seen the hijacker get subdued by passengers - in one instance probably because there happened to be six police officers aboard; in the other instance it was a lone hijacker with a nail file...
Incidentally, despite 9/11, the odds of surviving a plane hijacking are still very high - the persons running the highest risk of getting killed in a hijacking are the hijackers. As it happens, 9/11 did not result in a string of copycat hijackers - most hijackers appears to still plan to survive the hijacking.
Since I'm old, I remember the decades during which we were taught to cooperate completely with hijackers. Of course this was always bad advice, as was eventually made clear even to the idiots on TV. It seems possible that if no terrorism "expert" had ever appeared on TV, 9/11 could have gone very differently.
That said, things like taking your shoes off, taking your laptop out, removing belts, etc. really slow down the xray machine line.
I have no idea. To me, by far the most dangerous part of flying is the queue at the TSA checkpoints, especially at airports with particularly large checkpoints (I'm thinking EWR and probably ORD). I think some airports address this (SEA, MSP, JFK...maybe) by spreading out the checkpoints among smaller groups of gates to keep the volume of people at those checkpoints down. This is just my speculation, however.
I'd be curious to see how checkpoints have evolved over the last 14 years in terms of design and efficiency.
We can sit around and come up with thousands of possible attacks scenarios with less than 1% of the security that goes into preventing airplane hijackings. But that doesn't really matter. Airport security is primarily a political item, both responding to political pressures and fears, while generating entirely new ones.
Obviously any place where there are large groups of people would be a target for attacks of this kind.
If a plane goes down, it's reasonable to expect that everyone on board will die. It's less reasonable to expect that the blast radius of a device that was sufficient to down an aircraft would be sufficient to encompass an equivalent number of people in the security line.
I assume that's to prevent targeting concentrations of foreign tourists.