You have a right to protect your life and your property. Nobody who is willing to steal a phone deserves to live anyway. I say do away with them all.
Actually, you don't have a right (in most states) to shoot someone who robs you unless they threaten/use violence. Meaning if they snatch and run, you can't legally shoot them to stop their escape. Personally, I think that's absolutely ridiculous, but I don't write the laws.
Do you plan to, should the situation dictate, shoot somebody?
I don't have a gun and live in a state with pretty restrictive gun laws, but are you kidding me? If someone were to try to rob me at knife/gun point or were to break into my home when I was in it, abso-friggin'-loutely I would shoot them, and not just once.
I am all for non-aggression (not non-violence - big difference), but if someone else wants to aggress first, they've bought whatever comes to them. Honestly, I find it incomprehensible that anyone would NOT be willing to use lethal force to prevent grave harm or death to themselves or a loved one.