Isn't the point of the police to have a monopoly on violence?! I mean, I'm sure Walmart could create its own army if they had to, but ... do we, as a society, really want that?
Not sure about an army, but I think the point is that they are actively consuming a public service more often because they have cut their own costs, instead of paying for a deterrent themselves.
I don't believe that anybody has suggested that. What people have suggested is having more staff present, like Walmart used to have. Police aren't the only way to stop crime. They aren't even the best way.
I read a great article describing how Walmart does this. Companies who pay a living wage, like Costco, essentially subsidize Walmart by allowing them to pay low wages. Government Safety Nets like food stamps, medi-cal, etc., make up for the low wages. Thing is, these are paid for by tax dollars from employees at Costco who actually pay into the state treasury. Many Walmart employees are actually a drain on tax dollars. I'm at work and shouldn't be commenting on HN so here's the link to "Confronting the Parasite Economy. Actually read it here on HN, but it seems pertinent to the discussion.
http://prospect.org/article/confronting-parasite-economy