IDK, I think jokes about realistic threats can serve a purpose too, though it makes rather a difference if the person telling it is a potential victim or a potential aggressor. A similar joke to the PA one told by a woman would take on a different meaning. And even then, I think the best stance would be to say, "I find this funny, in ways that are helpful to me. It is perfectly okay that you don't find this funny, and I understand how it could be harmful. I'm sorry that you were hurt, and I will put up a general warning about what kind of humour can be found here."