Nothing necessary for Human survival should be controlled by a private entity: Food, clean water, shelter. Private corporations are raising prices while wages are going down. The median take home pay in America is $3,300 per month and the median rent is 61% of that take home pay.
And, just as mentioned above, neither should anything necessary to a functioning society be controlled by a private entity. There should be no privateprison that profit off increased incarceration. The private prisons will push to make more things illegal to boost their share prices, which go up when more people are in prison. That is why the United States holds 25% of the World's incarcerated by only comprises 5% of the World's total population.