In the Oregon mall shooting, if I am reading news reports correctly, a man with a CCW gun confronted the shooter shortly before the shooter took his own life.
Here's a list of other shootings where a gun owner shot or confronted the attacker:
http://www.volokh.com/2012/12/14/do...capture-kill-or-otherwise-stop-mass-shooters/
Would legal gun owners stop every single shooting from ever happening? No, and few people believe that would be the case.
Can legal gun owners use their weapon to possibly stop a shooter from killing more people, far sooner than the police? In some, perhaps many, cases, yes. It depends greatly on the situation at hand.
Is stationing an armed guard, or arming the staff, at every school the right and only choice? No, I don't believe so.
Some schools might benefit from having a guard, or armed staff, but that should be a decision the school district makes, not one forced upon them.
I don't support the NRA because I don't agree with their politics, which is the same reason I don't support the Brady Campaign either.
I'm rather displeased with the attention on media violence and gun availability, and the limited mention of the declining mental health situation in the US. Many of the shooters this year have been mentally unwell, and while most mentally ill people are not more prone to committing violent crimes, some are and those few would benefit greatly from a proper mental health system. By proper I mean one that offers long term behavioral therapy and not simply a buffet of drugs to experiment with.