If you have physical access to the box, you can always unplug it or destroy the unit. Where do you draw the line for the obstacle? Regardless, you may want to l

If you have physical access to the box, you can always unplug it or destroy the unit. Where do you draw the line for the obstacle? Regardless, you may want to look into running a dead man's switch on an external box that you don't physically control (AWS?).