Get a Restraining Order
Another English commenter going by the name Foldy suggested another course of action. “To put that fence up he must have trespassed on their land numerous times when he was erecting it. I’m sure he hasn’t got the time or money to pay for fences every five minutes. If he comes back and starts to build it again, then film him with commentary stating how many times he’s stepped over your boundary and then ring the police.”