It is easy, in the wake of any mass shooting tragedy, to fall prey to base emotionalism and believe that merely banning guns (or banning "bad" guns) would have prevented the tragedy. As shown over and over that is simply not the case. Obviously someone intent on murder is not going to be particularly hampered by some law prohibiting him from having a "semi-automatic assualt rifle" (a gun which, by definition, cannot exist).
What is harder, or has been up to now, is to show the ways good, responsible, law-abiding citizens are using guns to make the world better. Or, at least, to protect themselves.
Stepping up to the plate on this matter is the Cato Institute, a libertarian-leaning think-tank. They have put together this interactive map. What does it show? Instances of responsible gun owners using their guns to defend themselves, their family, their neighbors, and their homes. It's still a work in progress, and I'm sure it will be for the forseable future. Go check it out, and pay particular attention to the types of things against which people use guns to defend themselves.
With newspapers and web-zines publishing lists of legal gun owners names (and addresses), it only seems right that someone point out what those legal gun owners are doing with those guns.