Always the best course to pursue. But some people will let you talk to them about it, but will not anything about it. Especially if it costs them money, but sometimes even if it doesn't.
I've got a lifelong neighbor like that. I had to kill one of her trees before she'd remove it (on our property line, had caused damage to my property twice, which she'd ignored), and I had to rent a bucket truck to hack away at another one that's in her back yard, but grew to overhang my garage, driveway, and house. She's got a line of invasive shrubs and junk trees on the property line, too, and she refuses to get rid of them for 'sentimental reasons'. So last weekend I borrowed my nephew's brush hog while she was up at the cabin. She and her daughter came home on Monday to dirt where the shrubs and junk trees used to be.