Responsible gun owners should not have their rights infringed upon due to a few lone gunmen. Firearms are a necessity in a free society.
Reactionary measures to eliminate certain types of firearms in a nation built/founded by fire arms will not solve the "mad shooter" problem. The power needs to stay with the people (the citizens) at all cost, and the people should have access to the same type of hardware that the military could use against them if revolution was ever a necessity (god forbid).
However gun ownership should require a through background check, a face to face evaluation of the person obtaining the weapon, and training courses for properly owning and using them, much like obtaining a C.C.W. permit. All gun bans should be repealed and sensible measures should be taken