I think most would be happy just to make the purchase harder than it is. Banning or restrictions only affects those that follow the law. How do we stop people that would kill, maim, and injure people? Calling leo doesn't stop this at all, that 1st 5m makes all the difference. Just let anyone that can pass a test/background carry a gun legally in any state. Figuring out how to prevent those with mental issues from getting a gun. It would at least stop most mass shootings. Having a weapon to respond in kind seems like the only answer.