Hudson v. Palmer

Common sense would seem to dictate that prisoners should have fewer rights than people on the outside; otherwise prison would not be prison. Lack of freedom of movement, for instance, is a defining factor of prison. Likewise prisoners forfeit certain civil rights, such as the right to vote; a number of property rights (e.g. the warden might prevent a prisoner from receiving a gift of a gold watch for fear that his wearing the watch might encourage theft); the right to privacy with regards to his mail (though unreasonable censorship or restriction is unconstitutional); free speech (e.g., the prisoner cannot call for protests against the prison administration); and other rights.

Prisoners do have some rights, particularly under the Eighth Amendment prohibition of cruel and unusual punishment. They have a right to food, medical care, proper hygiene facilities, and adequate shelter. They also have a right to practice their own religion. Prison rules govern the administration of discipline and punishment in accordance with the Eighth Amendment.