In response to David Kopel's post below, my own view is that encouraging vigilante groups in New Orleans to "shoot on sight" whoever they believe is a looter without a valid necessity defense is tremendously dangerous. Such an approach would only help undermine the social order by turning New Orleans from a looting zone into a shooting zone.

  Among the problems is that looters can get guns, too, and presumably will try to shoot on sight the "armed citizens" that are trying to shoot them on sight. For that matter, armed looters will presumably say that they are "armed citizens" looking for looters, and will just shoot "citizens" and claim that be believed that they were looters. Who will be able to tell, given that the other side will by then be dead? The looter/armed citizen line is nice and clear in theory, but things get fuzzy and hard to reconstruct in practice. I would rather not encourage the latter to kill the former as a way of restoring social order.

  I strongly believe in self-defense, and this is particularly true in the horror of the developing situation like that in New Orleans. But encouraging armed vigilante groups to "shoot on sight" when they see what they think is "looting of concern" (as opposed to necessity-based looting, which is apparently quite okay and even laudable) in a city that is being evacuated seems to me, well, a really really bad idea. Others may disagree, of course, so I have enabled comments. Please note: I realize that these are particularly anxious times, but I am going to be quite relentless in deleting comments that are not civil, respectful, and on point.