Belle brings up a good question: what is most often the cause? Alcohol, very often. I don't dispute this.This is "AIR rage." But there's another type of rage. I call it "AIRLINE rage." Sometimes it happens in the air, sometimes it happens on the ground.

Some thoughts/observations:

I have a strong impression that AIRLINE rage is when people are at the suffering end of a major airine foulup with tickets/reservations/accommodation/seating, etc., with often multiple compounding snafus by the airline which leave even the best flyer exacerbated and then suddenly he/she encounters the it-was-your-fault agent, or the parochial dolt response: rage. (I am excepting the situations where its the passengers fault, and it certainly can be, as many agents can tell you).

As someone pointed to above, certainly sometimes being human correlates with such behavior. I have read many stories, even here, from seasoned travelers, with whom I empathize, and yes I wanted to break the agent's neck as well--albeit figuratively (no, I don't have a past history of abuse/violence). How often is this sort of thing a factor in air rage? What is it that makes people rage? I am going out on a limb here, but it surmise that it's often the airline and its personnel who exacerbate the situation.

It would be interesting to survey whether many of the air rage cases correlate with personnel who don't address/handle a situation/passenger well. Again, I'm not saying it's the top factor, but wonder how often? Experiences/observations? I usually find that passengers don't suddenly flip out by themselves, all alone, and start screaming; it's usually when engaged with airline personnel.

I'm all for protecting flight personnel in the skies. BUT, for example, I am sick and tired of the poorly trained ground personnel who threaten to call security when a passenger is really getting screwed over and persists about a situation, albeit in a composed manner. There have been stories about this on flyertalk. Or perhaps you've encountered the FA who threatens to call the police at not even the slightest provocation. Have you seen this happen all too frequently?

Thus, protect people in the air, okay, but I am leery of giving any broad license, or anything that might lead towards this. I'm being a bit vague here....Anyway, yes, let's protect personnel against AIR rage but I'm inclinded to give passenger's more rights so that we can avoid AIRLINE rage. I've seen much more of the latter.