In defense of AR-15 sales to the public
People like Piers Morgan make the point that we don't allow people to purchase tanks or 50 caliber machine guns to defend themselves from government tyranny, so why allow AR-15s.
The answer? Despite the technological advances since the Constitution was written, society still believes the core idea of public defense against potential tyranny applies. As noted by one Chinese Tienanmen Square dissident, a mass number of armed citizens would indeed be able to turn back a modern army -- unless that army was prepared to level a whole city. (The quote is "The argument that a man with a rifle has no standing against the military technology and machine of today" is ridiculous -- 20 million residents of Beijing would have quickly proved that wrong had they been armed in 1989.")
The argument for allowing citizens AR-15s is the concept first advanced by France with its Force de Frappe. In 1958, deGaulle was concerned that the U.S. would not protect France from a Soviet invasion. As Wikipedia notes -- and is critical to the discussion here: "The strategic concept behind the Force de Frappe is one of countervalue, i.e., the capability of inflicting to a more powerful enemy more damage than the complete destruction of the French population would represent. The enemy, having more to lose, would therefore refrain from proceeding any further." de Gaulle himself stated: "Within ten years, we shall have the means to kill 80 million Russians. I truly believe that one does not lightheartedly attack people who are able to kill 80 million Russians, even if one can kill 800 million French ..."
This, along with the facts that the AR-15 has indeed been used multiple times for home defense, and is virtually never utilized in crimes, is another reason we should allow AR-15s to the public.