Many people think that having more guns in public is a good thing, that if more people were armed, those with bad intentions would be less likely to act.  In theory, it sounds great.  The reality of the situation is something altogether different.
Here is an 
article: 
 Combat Vets Destroy the NRA’s Heroic Gunslinger Fantasy
 written by people who routinely use guns as part of their job.  It raises some very important points about what happens to people when they are actually in a shoot out.  Its very easy to shoot a paper target, but when that target is shooting back, and you know it, everything changes.
A few quotes:
" 
Retired  Army Sargeant Rafael Noboa y Rivera, who led a combat team in Iraq,  says that most soldiers only function effectively after they’ve been  exposed to fire a number a times. “I think there’s this fantasy world of  gunplay in the movies, but it doesn’t really happen that way,” he says.  "
 Blair’s  trainees run through a number of real-world scenarios—“force on force  training” that’s designed to “inoculate” officers against the problems  people naturally encounter in high-stress situations. That stress  response, says Blair, includes “tunnel vision, audio exclusion and time  dilation,” and one would expect people who weren’t trained in these  situations to “freeze up or not know what to do, and to have difficulty  performing actions correctly.”				 					 					 
 
Weekend-long tactical training courses for civilians are growing in popularity.  But these courses offer only a shadow of what’s required, says David  Chipman, a former agent with the Bureau of Alcohol, Tobacco, Firearms  and Explosives (ATF). Chipman, who spent several years on the agency’s  SWAT team, says, “Training for a potentially deadly encounter meant, at a  minimum, qualifying four times a year throughout my 25-year career. And  this wasn’t just shooting paper—it meant doing extensive tactical  exercises. And when I was on the SWAT team we had to undergo monthly  tactical training.”				 					 						 
It has long been my contention that people should not carry in public.  It creates more problems than it solves.  The 2nd amendment says that as part of a well regulated militia...  What is a well regulated militia?