I was locked up in the feds, and the last two years I was there they went to this policy. Let me assure you if did absolutely nothing to stymie the flow of drugs. There are a hundred different ways people get stuff on the inside, and even if those hundred different ways were stopped there would be a new hundred in no time. The quality of the mail scans were terrible. Problems like missing portions of letters and B&W scans of greetings cards (which BTW is against copyright laws). I can't speak for the state level, but as far as the federal level the prison system is 0% rehabilitation. It is a profit mongering machine if you follow the money. For example the judge that sentenced me has a stake in the unicor federal prison industries factory I worked at, as well as the halfway house I was required to stay at when I got out even though I had a job and home immediately upon release.