http://www.salon.com/2014/04/15/america_on_lockdown_why_the_...
https://www.opensecrets.org/news/issues/prisons/
http://thinkprogress.org/justice/2012/08/03/627471/private-p...
There are a lot more out there across the years. The general impression is one of an 'industry' seeking to expand its operations and that just doesn't sit right to me as an outsider.