I don't think that students should be encouraged but they should definitely not be discouraged as long as they don't harm others in the process. I think you should rather teach them how to lead a constructive debate and how to work with data and science. But I do think that you should teach them what reliable sources are, which news agencies have a tendency to lie and most importantly what's going on in their country and the world and maybe have some sort of debate in a controlled environment every once in a while.