Dan, Cajun Bandit sells cylinder locking kit that attaches your mid section to the legs. I haven't used it or seen it in person, so I can't offer an opinion.
Chris
Never used them . Looks like one clip to me , that has to go under the door and hook to the opening . Would have to have the lid hinge across from it to prevent tipping . Don't think it holds it all together , like for lifting .