I didn't read the "walmart" thread but... Criminals getting harmed isn't a bad thing. It makes all others reconsider trying to do the same.
And it's my belief that if someone tries to make victims of people, it's only right that he risks becomming a victim himself.
It's easy for fools to criticize a man's actions when they weren't put in the same positions themselves. I like how such people analyze things as "it was so obvious" when they're just reading an article after the incident and not caught up during the action when peoples' lives are at stake and the facts haven't been thoroughly investigated but you only get what you observe.