Might want to think that through if you ever plan to remove your tailgate. Would also recommend place a split piece of radiator hose between the clamp and the painted surface to protect the paint job and prevent future corrosion...For less than a buck get a hose clamp, tighten it over the right hand hinge. Then take a dremmel and grind the bolt on the clamp down far enough that neither a Phillips nor socket will work on it.
An opportunistic thief would need to cut off if with a power tool.