The latest issue of the Journal of Libertarian Studies contains an excellent review by Bill Anderson of Judge Andrew Napolitano's book Constitutional Chaos. Anderson quotes Napolitano on gun control:
Just think what might have been avoided if law-abiding Americans had been armed on those ill-fated planes on September 11th 2001.
Aha, Judge, I gotcha! I found the flaw in your reasoning: if the passengers had been armed, the terrorists would never even tried to hijack the planes.
Uhhh, waitasec...