We need some real thought to go into this from people who actually understand the issues at hand. This knee-jerk reaction will not solve anything, and doing something for the sake of doing something only creates a false sense of security that will inevitably leave us more vulnerable in the future. Why do we expect a mass-shooter to limit himself to legal devices with which to kill? What do we do when someone uses an already highly illegal (but easy to fabricate) shoestring machine gun? Silencers, short barrel rifles, AOWs, machine guns...they're all highly regulated but easy to manufacture with minimal effort and tools. We've just been lucky that mass-shooters up to this point aren't machinists. Let's address the real issue here: mental disorder. If the government were truly capable of regulating safety, then murder, suicide, rape, drunk driving, drug use, and racism would no longer exist.