I would pursue the heck out of the potential trespassing charges but that's about all you can do. Unless this guy's running a business on land that's not zoned commercially of course??? Then you might have something. Sadly it is his land to destroy. But a lot of good comes along with that right. It also gives you the right to buy your own land and create your own hunting sanctuary.

I ditto becoming the crazy neighbor guy but not to the point of obsession or where it consumes you. Just have some fun with it. You can walk around in camo fatigues with your remington and night vision goggles and an aluminum foil hat you claim keeps the government brain waves out.

I would put up all sorts of threatening signs regarding what will happen to trespassers and survivorsand run barbwire all along the border of the land. At least make it somewhat visually deterring and painful for them to enter your own land.