 So I draft a letter for that person. I send it to the property owner and I tell them, hey, your tree's in dangerous condition. If it falls, you're going to be liable. If it falls later, you show that letter to the court. It's great evidence they were on notice. Does that require you to do it by certified mail? There's no requirement that it's sent anyway, but certified is always the best because you can show the green card receipt later. If you do something like email or regular U.S. mail, someone can always say, oh, I never got it. I never opened it.