I don’t think this is too new, but I certainly missed it.
For the busy viewer, watch the first 15 seconds or so to get the idea, then skip ahead to 3 minutes 1 second to get to the meat of it.
(Hat tip: Frischer Wind)
It seems to me that all you need, with these devices, is a kind of “smoke detector” that detects anything wrong … terrorists, disgruntlement among the passengers, running out of the preferred dinner option … whatever. On activation, the “smoke detector” (let’s call it a “Potential National Security Situation Detection Device”) .. simply activates all of the EMD technology. Everybody goes down at once.
But really, the easiest way to do this is going to be to plant a chip in everyone’s head.