If I am not mistaken, there has been a time or two when governments have participated in genocide. I’m not going to crunch the numbers, because I’m sure others have already.
http://www.hawaii.edu/powerkills/NOTE5.HTMWithout looking, I would guess that the number of people killed by governments are pretty staggering, making school and mall shootings insignificant (except for those involved). Kind of like the carbon dioxide released by a big volcano eruption compared to a gas powered leaf blower.
If we really want to protect the children, we should ban all governments. You never know when a government might snap and go crazy on its people.
(Actually, civilian disarmament might be a valid indicator since this tends to happen prior to most genocide.)
Logical fallacy: some governments (not only participated but also) initiated and enforced genocides so all forms of government should be banned.
I know it's easier to think that way, but simplicity isn't always a solution when you want billions (or even simply hundreds) of people to share natural resources and make a life for themselves.
A government, even a tyrannical one, is always tolerated by its population. All governments fell when people organized themselves. If they don't have guns, it's only a
trivial matter: part of the military will always defect (they don't like to kill their own family and friends usually). When people really value freedom and are willing to die for it there's nothing a government can do even with a large military advantage: the bigger the guns they have, the more damage they can deal them when soldiers defect. Today tyrannical governments only maintain themselves by aggressively spying on their population and keeping it from organizing as free thinking groups. When your government knows where you live, who you communicate with, where your kids go to school, which path they use and sends an anonymous thug to your door saying "you know we know that you are in contact with these anti-patriotic criminals, that's a bad idea that could bring misfortune to your family..." that's far more effective that sending him with a gun to kill everybody in sight. That's how they do it in China, mostly they don't even have to send someone as people know they are watched and most keep their heads down. Even though there are hangings and people "disappear", this is by far the exception and mainly used to make the threat real, it's much more effective to spread fear and division than creating martyrs.
This is why you should be much more worried by governments spying on you than governments banning guns. This is the first step in tyranny which makes all others trivial enough. If they allow the situation to degenerate and come to open kidnappings and killings they don't stand much chance.
We discussed guns as a last line of defense against corrupted governments, but last time I checked in the US you were a democracy: why do you keep voting for corrupt people removing your liberties? If there isn't anyone running for public office you can trust and you are so convinced the ones who do are after you, why don't you do it yourself and educate your fellow citizens instead of grabbing a gun? Is it so much better to limit your safety to keeping a gun on you at all times and have people with gun you trust around anyone or anything you value even when you don't have a single clue where, when and against whom you will have to defend yourself?
You are fighting a lost battle, guns were the only defense weapons available to small isolated groups in an hostile environment ages ago when dying young and violently was commonplace and seen as inevitable. Today if you want something better than the wild west what you need is knowledge, trust relationships and involvement in the political process. The threats will always be too big to handle when they come if you ignore them and let them grow while training yourself at the gun range, no matter how big the gun you train with is.