That just sucks. I hate leaving a trailer on my truck when I have to leave it someplace. I use a locking pin for the receiver and lock pin on the trailer tongue. I guess I never thought of the SOBs removing the nut on the ball. But they'd have to have a good wrench to do it. I use a 2' long wrench just for use with trailer ball and I torque that sucker down way tight. But I guess if they are determined enough, they'll do whatever it takes.