There are too many guns already out there for banning them now to be in any way affective. It's part of our constitution that new laws are not retroactive. If the law today was that i'm allowed to buy a gun and I buy one but the next day it gets changed to guns being illegal they can't take my gun away or charge me for having it. They can ban the use of currently owned guns, but what will that do to stop this? They are already breaking the law in an extreme way, throwing one more in the way isn't gonna do much.