You wouldn't be able to ban guns all around earth. It would be impossible to ban them all. Here is some evidence to my side of the story “Collecting them would be an impossible task to do.”
When a person tries buying a gun they need to do a background check first to see if it would be safe or not for them to even buy or have a gun. There's a part of this where someone said “Hidden Gun Ownership is rare and strictly regulated” which is evidence to my side of the story on this situation too. So gun ownership should be strictly regulated. Guns should be used for hunting or sportswise.