It's difficult to think about locking people up as a business model, but for private prisons the money is in inmates.

Now the largest private prison operator in the nation -- Corrections Corporation of America (CCA) -- is blanketing states with offers to buy their state-run prisons... provided, of course, that the states guarantee a steady flow of prisoners.

Thankfully Montana corrections officials declined this offer.

The Montana Department of Corrections did receive a letter from CCA, confirmed the department's communications director, Bob Anez, but it isn't interested.

"We indicated Montana is not selling any prisons. As you may know, the state policy is that we are not interested in more private, for-profit prisons," Anez said in an e-mail to the ACLU of Montana.

Montana currently has one private prison in Shelby and is seeking to add beds systemwide. No decisions have been made about where those beds will be located, but the ACLU  is happy that they won't be located in a new, privately owned facility.

Private prisons are troubling in many ways, starting with the fact that they rely on a steady stream of inmates to make a profit. According to CCA's 2010 Annual Report: "The demand for our facilities and services could be adversely affected by...leniency in conviction or parole standards and sentencing practices."

But the ACLU of Montana and Montana taxpayers are very interested in such programs which keep more nonviolent offenders out of jail and save the state money on incarceration.

And for those who think that privatization is the answer to saving money, studies prove otherwise.

Ohio took up CCA's offer and sold the company its Lake Erie Correctional Facility for $72.7 million. Though CCA says the sale will save the state $3 million per year, outside analysts have found that it will actuall cost the state $11.4 million more over the next 20 years than if it had continued to operate the prison on its own.

And in Arizona,  officials found that privatizing prisons offers little if nothing in savings, with some prisoners costing more.

Finding more opportunities to place prisoners in community corrections is the way to save money, not putting them in private prisons.