What does it mean to say we are entitled to our opinion?

What does it mean to say that someone is entitled to their own opinion? People say that a lot, but I am not sure what they are saying when they say it. To say I am entitled to something, I take it, implies someone might want to take it away from me, and either shouldn't or shouldn't be permitted to. But who might be taking out opinion away from us, and what kind of protection do we need from whoever it is that is trying to take our opinion away from us? Further, it isn't clear what an "opinion" is in this context. That can mean a personal preference that can be neither true nor false (country music is better than rock-n-roll), or it can mean a claim which can be true or false, and for which there can be evidence, but is not completely settled to everyone's satisfaction. Consider the "opinion" of Kirilov in Dostoyevsky's The Possesed, who believes that "he who kills himself, becomes God." Is this something that Kirilov is "entitled to," even if it may lead him to suicide (and did, in the novel).
And then we can look at the various means that people might use to get people to stop holding an opinion. We can torture someone to make them change their minds, we can disown them or give them a lot of disapproval and make them feel bad for believing what they do, or we could try to give them reasons why their beliefs are false. Does our being entitled to our opinion mean that no one should attempt to give another person a logical reason for rejecting what he or she currently believes? I would say, certainly not.

This essay is entitled "Sorry, but you are not entitled to your opinion."

I believe I have linked to it before.