Hmmm, I can visualize the increase in main street gunfights now:

A year after Florida became the first state to allow citizens to use deadly force against muggers, carjackers and other attackers, the idea is spreading. South Dakota has enacted a similar law, Indiana Gov. Mitch Daniels plans to sign such a measure today, and 15 other states are considering such proposals.
Dubbed “Stand Your Ground” bills by supporters such as the National Rifle Association, the measures generally grant immunity from prosecution and lawsuits to those who use deadly force to combat any unlawful entry or attack. Several states allow people to use deadly force in their homes against intruders; the new measures represent an expansion of self-defense rights to crimes committed in public.

This should apply to intruders like these as well!

NB: That south dakota is on this list does not constitute any reason to put that state back into your travel plans.