Me, I thought they called it that after the shout soldiers give when they jump out of airplanes. As an airborne attack by a very gung-ho kind of team, I thought the name was meant to show their instant readiness to do or die.
I guess the Scriptures are shown to be right again: Unto the pure, all things are pure. (Although, in my case, maybe it's just, "unto the oblivious," but whatever.)