John’s entire house is now booby-trapped. The doors, for instance, are surrounded by four nozzles that in theory will fire four jets of propane-fueled flames, instantly turning any intruder into an intruder who is on fire. Won’t this almost certainly catch the exterior of the house on fire, you ask? Yep. And, once the flaming intruder stumbles inside, the interior of the house will also be on fire.
