Private security functions in almost all aspects of modern urban life, even though the public is hardly aware of the existence and development of the private police. The discussion examines the evolution of private policing services and the meaning of such concepts and private peace and property. It contrasts the objectives and responsibilities of both private and public police, pointing out the functions and limitations of each. Impacts of the growth of private policing are outlined, and the relationship between the expansion of modern corporate business enterprises and the need for private security services is examined. A total of 26 references are given. (Author abstract modified)