You have no right to “[know] just who has a gun in public.” Your hoplophobia does not get to restrict my rights.
Odds are good that you walk right by several people a day who are concealed-carrying and who are safer for it. Concealed carry makes most people more comfortable as they don't have to see the scary “death machines.”
All that being said, I must say this is one of the most ignorant and unrealistic things I have ever read. It is obvious that you are one of the very few, very loud, and very obnoxious anti-gun zealots we have to put up with.