Gun locks
From Conservapedia
A gun lock is a device which inhibits the use of a firearm, sometimes for safety purposes. While they come in a variety of forms, all serve the purpose of preventing the gun from being used by anyone other than the owner. Requiring expensive gun locks on all firearms can be a form of gun control.
Flaws
John Lott said, "... it's not in everybody's interest to have a lock on their gun. If you live in a safe area and maybe have young kids, that might be fine. But if you live in a city, even if you have kids, I don't think it's really the wisest thing to have the gun locked up, because you're not going to be able to quickly access it to defend your family. And when you compare probabilities, accidental gun deaths in the home are trivial compared to the rate at which other types of deaths occur from crimes where innocent victims are attacked and a gun would benefit them."[1]
