I tend to be a people-pleaser, and I avoid conflict like the plague. Because of this, I've spent a long time being walked on.
This morning though, my neighbor took it on himself to wait until the kids and I went out and he set up a fence line inside of our property (by about 20 feet.) He then mowed down my daughter's little wild area (a science experiment named 'bugland') she's been visiting daily all summer and broke her scooter- I suspect he ran over it with the mower or threw it across the yard- I found it in two pieces.
When confronted, he started yelling and claiming he had every right. I called the Sheriff. For me, that's HUGE. I was once assaulted by someone impersonating a police officer. When reported, the police dismissed me as lying. Since then I've been terrified of police involvement- I don't even drive a mile over the speed limit- ever!
The Sheriff agreed with me, and made the neighbor take down the line. If he wants to contest it he has to hire (at his expense) a survey company. The GPS the sheriff was carrying agreed with the established line- obviously, only a legal survey can tell for sure.
I filed a separate claim for the property destruction (DD's scooter) and the neighbor was charged with trespassing. It helped that he claimed she'd never ridden her scooter all summer and on the front page of last week's newspaper was a picture of DD and her best friend at the park using the scooter. On her knee was the scab healing from a fall she took that day- and the reason she'd put the scooter away (carefully near a tree at 'bugland' .) The Sheriff pointed out that if they wanted to lie, they probably shouldn't do so to him when the proof is a front page picture in the newspaper.
The sad thing though is that if he'd simply been civil and knocked on the door to say he believed the line was in a different place, I wouldn't have argued, I would simply have looked into it when I was able to. Because he decided to sneak and lie, I decided not to be walked on.