@Telepathic.Geometry Automatic weapons are as deadly as other kind weaponry that uses bullets, RPGs are expensive as hell so you ought to buy a simple 1911 and use the rest of the money to buy a good surveillance system. And what kind of cannons we are dealing with, exactly?
I am in favor of arming SANE people who want to use guns as A) A safe, monitored and legal sport or B) A mean to protect households and family members from degenerated lunatics. Gun policy should be more strict but outlawing them wouldn't do much, people would still be able to illegally arm themselves. Since humans created arms, we weren't able to properly control who would use them and who wouldn't, but we never did (or will) completely block guns and melee weapons.
In Brazil we made some guns legal, like Shotguns and Pistols, but there are people who own Assault and Sniper rifles (not only the favela folk if you are wondering) although there were lunatics like the one in Sandy that did attacks to school and even banks. Better police enforcement would completely exclude the necessity of guns if you ask me.