Stubborn - the referenced council only served the purpose of determining who held the valid and legitimate claim/election. It even made the point that it(the council) required ratification from the pope of the outcome. So, the council did not formally depose a pope. Cantarella's post is helpful, but does not supply us with a course of action for out times(we have no rival papacy, and still no historical precedent). Cantarella's opening statement rests solely on the opinion of theologians. And, I agree with you stubborn, if a pope can be formally deposed by the mob, then he is not the supreme head. You would think that if it were possible, God would open that door for tradition to carry it out(being that we are dealing with papal heresy). But, instead, tradition is split in so many different directions, that there is no way a general council could be prepared and effective among us.