If it's as bad as you say it is, google your DNR for the number, pick up the phone and turn him in! It's that simple. You obviously know who he is and know where he lives, it shouldn't be that hard for the DNR to locate him and file harrassment charges on him. Other than that, there is nothing that will be done about it and you'll just have to like it or lump it!
If someone would be that rude and ignorant to me, I'd turn them in faster than they could gut a deer!