Well, Samuel does it. He denounces Eli and becomes himself priest and leader of the people of Israel. And as a result of his very long life of leadership, he calls Saul to be king and then deposes him, throwing Israel into a turmoil of confusion that leads to the kingship of David, a kingship that ends in adultery, lying, and murder.
Being a prophet has decided dangers attached to the work; hazards duty pay called for! To claim to speak for God places one in the most precarious of positions. Can any human finally know if the words that fall from her lips are in fact the words of the Almighty? Can anyone be absolutely certain that what he says even faintly echoes what God would say to an anxious world? The Bible offers only one direct way that one can tell whether a prophet is really a prophet of YHWH. In Deuteronomy 18:21-22, it says, "How can we recognize a word that YHWH has not spoken?" And the text answers the question like this, "If a prophet speaks in the name of YHWH but the thing does not take place or prove true, it is a word that YHWH has not spoken."
Well, there is a most unhelpful bit of advice! Lacking a crystal ball, just how am I to anticipate whether that person's words or this person's ideas are in fact God's words and ideas, if all I can do is wait and see whether they come true or not? I fear I am left with my limited human perceptions after all. Could I have told whether Samuel was actually speaking YHWH's words, if I had overheard him in the temple of Shiloh? Not likely. All the more reason to listen with care to those claiming a direct phone line to God; they do not have one any more than I do. Yes, Samuel is remembered as a great prophet of God, but like all such people, he must be assessed and probed and tested and evaluated. And as for those of us who stand up and announce that we are spokespeople for that same God, we must expect the same reactions.