No, I have not, but maybe that is because I had only written one hub before:P
Anyways, if someone leaves a hostile comment on one of your hubs, ignore it. Yes, I agree that individuals should be entitled to their own opinions, but to some extent. If the comment is a nicely written, argumentative piece meant to simply share the opposing opinion of one, the author of the comment has a right to do so. But if the commentator leaves a so-called "hostile" comment entwined with swearing, discriminating, inappropriate, etc hints, he or she should not be allowed to do so. You, however, cannot do anything about the intentions of others, so I suggest simply deleting the comment and ignoring him/her, because associating with such rude, unworthy jerks will not bring any good. Remember, you have your opinion, too. Don't let them bring you down.
Good luck! And hope your comment box fills with friendly notes. :)