But if you don't do anything and they get hurt on your property they could sue you. We had people try and do that when they were snowmobiling in my corn field one winter and one fell off. Only thing that saved us was the no trespassing signs everywhere. What about the plastic anti roost strips that people use in barns to keep birds from landing. Can't see that being illegal in anyway... You just don't want bird crap on your fence. Anything else is just coincidental. Lol