A million years ago, there was a Columbo episode where a violist was killed by a gun positioned outside his window with a trigger rigged to a tuning fork-type device. For some reason, that killing-by-remote has always stuck in my mind. I've seen a flying, gun-toting drone here or elsewhere and wonder how long it will be before we have drone assassinations --if not already. Kim Jong Nam's killing could have been easily done by quadcopter, I think.