Incitement or gagging

Shalom Aleichem Rabbi, I would like to know what you think about the possibility of arresting people or firing them for their opinions during this time.
Such as in situations where people say that the terrible massacre happened because of the occupation, is it moral or democratic to arrest them for that? Where is the line between critical opinion and incitement to terrorism?
I want all the radical leftists to be people who are hurting us greatly during this period, and on the other hand, I'm not sure we're allowed to tell them to stop talking, because then democracy would have gone.
What is true and what does the rabbi suggest?