Private prisons have lobbied repeatedly and successfully to raise prison sentences to unreasonably high levels. It's contributing to use having the world's largest prison population per capita.
In Pennsylvania judge Mark Ciavarella Jr. was recently convicted of accepting bribes from a privately owned prison in exchange for finding juveniles guilty because the prison made more money the more prisoners they have.
Giving these people financial incentive to lock up Americans just creates a ton of problems, corrupts justice and needs to end immediately.