The most dangerous man to any government

The most dangerous man, to any government, is the man who is able to think things out for himself, without regard to the prevailing superstitions and taboos. Almost invariably he comes to the conclusion that the government he lives under is dishonest, insane and intolerable, and so, if he is romantic, he tries to change it. And if he is not romantic personally, he is apt to spread discontent among those who are. ― HL Mencken

And usually these troublemakers are the ones who need to be muzzled through suppression of speech and expression.