Privatization of prisons is nothing more than formal restructuring of gov spendings. Call it what you want, the money flow is still the same:
1. Force people to give up 40-50% of their income (directly and indirectly via sales taxes, import/export regulations, licensing, patents etc).
2. Give that money to some other people to do stuff that you want to do.
Always following the money is good advice, and we're both doing that. I'm just doing a little more Occam's razor.