I'm sorry, but I can't for the life of me understand why some people are so hoplophobic on this issue. The mere presence of a firearm carried by a responsible law abiding citizen is no more of a danger to others than is a responsible citizen driving a Ferarri capable of going 180 mph. Unless and until said person commits an unlawful act with either inanimate object, there is no danger posed to anyone at all.
Perhaps with the same logic as some of you put forth here, we should require all male park goers to submit to castration. After all, we sure wouldn't want a bunch of people armed for rape running amok in our parks, would we? It's just a matter of time until a rape occurs.
If you can't see the comparable silliness of that arguement with yours of not allowing lawful citizens to exercise their 2nd Ammendment rights, then you are either hopelessly naive, or willingly cognitively dissonant.