We worry about a lot of things in computer science that has never happened and may never happen. There's common discussion several times a year on HN about the ethical rights of artificial intelligence or lab-grown brains. It's still important to worry about things that haven't happened and may never happen, if only to ensure that they really do never happen.
It's completely plausible that a company could sue over this farmer's fear. Just because it hasn't happened doesn't mean it won't happen, or that we shouldn't worry about it.