"Proprietary prisons" are secure confinement facilities managed by privately owned companies under contract to government. As a matter of propriety, the opponents of such prisons have argued that it is improper for any entity but the government to operate a prison. This argument can be countered, however, since the authority of the State to imprison is originally derived from the consent of the governed and may, therefore, with similar consent be delegated further. Moreover, that authority is not absolute but is subject to law and the requirements of due process, whether it is exercised by salaried State employees or by contracted agents. Regarding cost, there is not yet sufficient evidence to support generalizations about the comparative costs of proprietary versus government prisons. The audit of a proprietary prison in Hamilton County, Tenn., however, found a significant dollar difference favoring private management for each of 3 years. Private prisons will not, and should not, reduce the responsibility of government for imprisonment. It is not likely that in the foreseeable future such prisons will replace government in the total volume of prisoners held and number of facilities managed. 10 references.