photoshop's upsampling will work well enough for anyone's needs when a good image is fed to it. The 10mp requirement is based on crappy digicams and ignorance on the part of the person writing the requirements.
Legally owned guns aren't really used in crimes. There are quite a few statistical studies to show that.
Don't be worried about the people that legally own guns (even when they buy them for self defense). Worry about criminals.
Anyway, not the place, so I'll drop it.
As far as I know that data doesn't exist, and would be darn hard to come up with. How many crimes that are averted get reported?
As to what the quote is saying, it's a fairly popular quote among firearm enthusiasts.