Many years back, I put up a tree stand on my property around 100 yds in from a well posted property line. I showed up early on opening day of buck season only to find another hunter in my stand!
He claimed the stand was his and he had permission to hunt there. I told him it was my stand on my land and I had not given anyone permission to hunt. "Prove it" was all he said as he raised his rifle!
I saw no sense in arguing with someone with a loaded gun. I turned and walked away saying "we'll let the police sort it out". I watched from a distance as he left in a hurry.
It never ceases to amaze me the nerve some people have!
Had something similar to me.
Two idiots were walking our property line hunting tree rats. The were shooting into our trees and in a direction where rounds might hit nearby houses. I first heard them when I was running the chainsaw. The first round or two I questioned what I was hearing because of the hearing protection and the sound of the chain saw. Then I saw the two idiots and they had been firing over my head with a .22 and a 12 gauge.

No way could they not know I was there. I was wearing an orange chainsaw helmet and chaps. Not to mention the freaking sound of the chainsaw.
I was not happy.
So I put up the chain saw, got some different safety equipment, and went to talk to these idiots. Standing right next to a No Trespass/No Hunting sign, they lied to my face with the "We have permission to hunt here." and "My daddy and I have always hunted this place."

They walked by at least 4-8 posted signs.
I was firm with them, but polite, that they were on my land, they most certainly did not have permission to hunt, I had never given anyone permission to hunt, and they needed to leave. Then I lectured them on how they were giving hunting a bad name by trespassing and shooting in the direction of houses. Never saw them again.
I don't recommend people do what I did, but I have the training, experience, and equipment for this sort of thing. If I had had the time, I would have called 911 and let deputies handle these lying fools, but these idiots were actively shooting near my house and directly at others. They could see our house ,but the near by houses are not viewable from where they were shooting, but rounds easily could have impacted in other peoples yards or homes.
Later,
Dan