So let me get this straight. People commit violent crimes and our problem solving capacity is limited to the methods used to achieve these ends?
Do we really have to be so simian about this? Lashing out at our tools when someone uses them irresponsibly does us absolutely no good.
The best answer if we are going to speak in such a limited scope is to allow for citizens to defend themselves from the mis-users and deviants. The only other alternative is building satellites that beam rays of pacification on everyone. Good luck with that.