Democratic presidential contender Sen. Bernie Sanders on Thursday introduced a bill to ban privately run prisons, citing a "perverse incentive" by the "private, for-profit prison racket" to increase the number of Americans incarcerated, reported USA Today.

The Vermont independent's "Justice Is Not For Sale Act" is co-sponsored in the House by three Democratic representatives - Raúl M. Grijalva of Arizona, Keith Ellison of Minnesota and Bobby L. Rush of Illinois.

"Keeping human beings in jail for long periods of time must no longer be an acceptable business model in America," Sanders said in a press release. "We have got to end the private prison racket in America. Our focus should be on treating people with dignity and ensuring they have the resources they need to get back on their feet when they get out."

Within three years of its implementation, the measure would ban federal, state and local governments from contracting with private companies to operate prisons, and would turn over some 100,000 inmates currently held in private prisons to federal authorities, according to the Huffington Post.

The legislation would reinstate the federal parole system, abolished in 1984, and do away with the rule requiring that Immigration and Customs Enforcement maintain 34,000 detention beds, which cost taxpayers more than $5 million per day, or $1.4 billion per year, according to Sanders. It would also work to reduce high fees for prisoner services such as phone calls.

Private prisons were initially created to reduce costs and prevent dangerous overcrowding in public facilities, but now hold 19 percent of federal prisoners, according to the Christian Science Monitor.

Criminal justice reform advocates contend that the $5 billion a year private prison industry has a financial incentive to lock people up, which reduces motivation to rehabilitate prisoners since companies can make more money by keeping them jailed.

"The profit motivation of private companies running prisons works at cross purposes with the goals of criminal justice," Sanders said. "Criminal justice and public safety are without a doubt the responsibility of the citizens of our country, not private corporations. They should be carried out by those who answer to voters, not those who answer to investors."

Each year, the private prison industry spends millions lobbying for harsher sentencing laws and immigration policies that fill its beds, according to Ellison, who added that incarceration "should be about rehabilitation and public safety, not profit."

Taxpayers pay about $80 a year to incarcerate 2.3 million people, according to the lawmakers.