I read a story a while back that a dude had someone that kept stealing the gas out his truck and couldn't get the cops to do anything about it. He grounded the truck and hooked a extension cord to the truck and plugged the other end in. He caught who was stealing his gas, was laying dead next to the truck, but blew his truck up in the process.
Need to hook a tazor gun aimeed about nut high with a trigger switch hooked to the gas cap.