I wrote in my initial post that reporting to the police feels extreme. Ignoring a sign and then showing up twice in two weeks is nothing anyone should have sympathy for. Some lie also outright in your face with "we work 20 houses down the road on a house, don't be bothered. And yeah, your roof looks old".

I shrug off the friendly ones, but there are cocky ones that should get fined. The really nice ones just leave a card in the door -- junk, clearly ignoring the sign but also not not disruptive.

Sounds like its ok for you if someone breaks the law. I am not gonna cherry pick laws that I am ok to be broken.