sam harris: The Riddle of the Gun

Link: http://m.samharris.org/blog/item/the-riddle-of-the-gun/ (via shareaholic.com)

Suffice it to say, if a person enters your home for the purpose of harming you, you cannot reasonably expect the police to arrive in time to stop him. This is not the fault of the police—it is a problem of physics.