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.
I'm not a giant fan of harry potter, but I have 4 kids...I buy collectors editions of any book I buy if it's available, just because I'm like that. So far, it's paid off. I've made over a grand from stephen king
Amazon.com: The Tales of Beedle the Bard, Collector's Edition (Offered Exclusively by Amazon): J. K. Rowling: Books
This is the coolest collector's edition of anything I've ever gotten, hands down.
That said, I'm not arguing music doesn't have information above 15khz, or that it's useful. I even used HF emphasized microphones to make my best recordings back when I used to do such things. Helped offset the rolloff distance caused.