I see it like this. If I had a gun, I would feel somewhat safe. As mentioned before, in England it's the "gangs" that carry them, and they commit senseless murders with them. Now let's put it like this. If you wanted someone dead for whatever reason (mainly cos he mocked you in a little youtube rap he made, like most things in England) would you go up to him and shoot him if you knew he had a gun? My guess is no. Would you go up to him and shoot him if you knew he had no gun, my guess is yes.
You would think twice about mugging, raping, attacking or even murdering someone who had a gun, and they knew you did.
I read in the paper about a town in Georgia that EVERY resident HAS to own at least one gun, unless they are disabled or strictly religiously against it. In that town, people think twice about burgling your home. Why? Because they would have so many guns pointed at them from the neighbours. I'm against it myself for those reasons.