"When I asked the railway authorities what principle they followed in deciding whether people may carry guns on trains, they said something very sensible. "It's not so much the item," they told me, "it's the behaviour."
There must be butchers, or even housewives, carrying deadly knives on trains. There must be doctors carrying syringes. There are probably still old ladies with hatpins. There is me with my gun. All have the power to kill, but none remotely intends to. We are not a threat.
A free society can function properly only if it works out what is a threat and what isn't. If it ignores threat, it will be attacked. If it treats everyone as a threat, it will grind to a halt."
Taken from the Telegraph; Ideology biggest threat to 'improved security'