Regarding "impulse" crimes--I don't see why such crimes are that much more of an issue on a plane than anywhere else. My understanding of psychology is naturally imperfect, but I don't think that a hijacking would be an impulse crime.
I could see why explosives would be more dangerous on a plane than elsewhere. However, people don't generally carry large amounts of explosives with them for no good reason, so explosives also don't lend themselves to impulse crime.
Other dangers, like getting shot or stabbed--something that is actually likely to be an impulse crime--are not much more dangerous on a plane than on the ground. Since we're perfectly content running the risk of being shot walking around outside, I don't see why airports would need special security just to prevent impulse crimes.
Of course, this is not an argument against all airport security. While I am personally against it, I would have to spend more time and do some research before being confident of making a compelling case against it. I'm just explaining why I think preventing impulse crimes would not be a good reason for tight security at airports.
I could see why explosives would be more dangerous on a plane than elsewhere. However, people don't generally carry large amounts of explosives with them for no good reason, so explosives also don't lend themselves to impulse crime.
Other dangers, like getting shot or stabbed--something that is actually likely to be an impulse crime--are not much more dangerous on a plane than on the ground. Since we're perfectly content running the risk of being shot walking around outside, I don't see why airports would need special security just to prevent impulse crimes.
Of course, this is not an argument against all airport security. While I am personally against it, I would have to spend more time and do some research before being confident of making a compelling case against it. I'm just explaining why I think preventing impulse crimes would not be a good reason for tight security at airports.