
Quoting
SChinFChin
Yes, there is something you can do.
You can erect your own wall, an inch into your property facing his, and your wall would obscure all his trespassing signs, which would all be in the space between the walls. Then, he can't come over and paste signs on YOUR FENCE. You might also check the wall height, and local codes, as in most jurisdictions, anything over 6 ft requires a variance, which is NOT automatically granted. In a town where I had a rental, it's six ft in the back yard, and no more than 4 ft. in the front.
In fact, I know someone who got into a fence dispute with a neighbor, the neighbor called in code enforcement, and the 6 ft fence had to be chopped down to 4 ft.