Years ago, people or groups of people would complain about certain shows on TV. Someone spoke up and just told them to shut up and change the channel, you don't have to watch it if you don't like it.
The simple solution here is to ignore and not respond (by anyone) to posts that are not on topic, offensive, hateful etc.
The main reason someone that is a dick, remains a dick, is because he gets what he is looking for. A response to his actions.