Thank you for the demystification, David...what you said.
I know of one major airline that intended to equip all cockpits with tazzers, and sent many pilots to school; a couple of whom I talked to thought it was very effective and a good use for it, but it was not to be. Probably too expensive. Meanwhile, up to a third of those pilots are now qualified to carry on board, but how many do it is unknown. The hassle of becoming and staying qualified, security concerns, and the liability of use of such is a PITA, yet some do. And, of course, the airline doesn't pay for the piece! I would like to see tazzers on board.
By the way, AFAIK, the sky marshalls are still riding the planes...a VERY expensive way to go. Anyone with an update on them?