moral obligation to teach Leftists not to harass others? It is an interesting question.
There is NO question in my mind that morality is context-driven. What is moral in one situation is decidedly immoral in another (shooting someone in battle vs. shooting someone in downtown NYC to take their wallet, for example).
So, here is my Devil’s Advocate argument: I would contend that we actually have a moral obligation to respond to things that are destructive of the social order (as the whole Mad Maxine “Get in their Face” mentality of public protest is), and even more, we have an obligation to respond to those things effectively and educationally: teaching those engaging in destructive behavior why that behavior is wrong. And what better way to do it than to essentially treat people as they are treating others, so that they can come to understand why it is bad?