I've had two guys break into my home, guns in hand, threatening to kill me if I didn't tell them where the cocaine was that whomever (can't remember the name) had. Guess what, I didn't know the person and had no drugs. They where freaking out and looked like they had been up for days, obviously trying to get more. I was lucky to get away while they searched my closets leaving me unattended for a few seconds. Now the thing is, I had enough time to grab a gun if I had one before they cornered me. If something similar happened today, I would be ready. Not that I would want to hurt anyone but the prior situation taught me a good lesson. Shot them. Don't even ask questions, no warning, just shoot shoot shoot.
This coming from a guy who genuinely avoids killing ants.
I guess you can argue "if no one had them" then we could counter "knives, bats, bow and arrow ect" I would go for the long distance weapons myself, even if I had to rig something up that shoots knives.
Until everyone in the world can respect all living things like I do, I can't trust them. Besides, there is a lot of Christians that threaten to kill me every single day. We all know I'm out spoken about this stuff, I take it a lot further in other public forums. My wall on Facebook alone would drive someone to kill me.