Here's a question: Why don't we want law enforcement to cost taxpayers money? It seems to me that we would ration it more were it costing us real dollars, instead of just the myriad externalities associated with criminalizing being poor. The calculus that's incorrect in privatizing government services is this. Companies don't exist to provide services; they exist to make money. Providing services is just a means to that ends, and there's nothing wrong with it on the surface. The problem is that their incentives and ours are not aligned.