Where I live (middle of the United States) the complainant would have to prove they had been doing all the maintenance on the disputed property for years. I don't recall the number of years but it is several.
Them demanding structures be torn down and windows on the human house be bricked over...
Has a survey ever been done? That would show true property lines.
I agree 100%.
That fence wouldn't even slow down most medium or large breed dogs let alone the chickens in the photos.