Police state is a term that originally designated a state regulated by a civil administration, but since the middle of the 20th Century, the term has "taken on the emotional and derogatory meaning of a government that exercises power arbitrarily through the police."
The inhabitants of a police state experience restrictions on their mobility, and on their freedom to express or communicate political or other views, which are subject to police monitoring or enforcement. Political control may be exerted by means of a secret police force which operates outside the boundaries normally imposed by a constitutional state. Robert von Mohl, who first introduced the rule of law to German jurisprudence, contrasted the Rechtsstaat ("legal" or "constitutional" state) with the aristocratic Polizeistaat ("police state").
History of usage
The term "police state" was first used in 1851, in reference to the use of a national police force to maintain order, in Austria. The Oxford English Dictionary traces the phrase "police State" back to 1851. The German term Polizeistaat came into English usage in the 1930s with reference to totalitarian governments that had begun to emerge in Europe.
Genuine police states are fundamentally authoritarian, and are often dictatorships. However the degree of government repression varies widely among societies.
In times of national emergency or war, the balance which may usually exist between freedom and national security often tips in favour of security. This shift may lead to allegations that the nation in question has become, or is becoming, a police state.
Because there are different political perspectives as to what an appropriate balance is between individual freedom and national security, there are no definitive objective standards to determine whether the term "police state" applies to a particular nation at any given point in time. Thus, it is difficult to evaluate objectively the truth of allegations that a nation is, or is not becoming, a police state. One way to view the concept of the police state and the free state is through the medium of a balance or scale, where any law focused on removing liberty is seen as moving towards a police state, and any law which limits government oversight is seen as moving towards a free state.
The Soviet Union and its many satellite states, including East Germany and those that were part of the Soviet bloc, had extensive and repressive police and intelligence services (such as the KGB); approximately 2.5% of the East German adult population served as informants for the Stasi.
Nazi Germany, a dictatorship, was brought into being through a nominal democracy, yet gradually exerted more and more repressive controls over its people in the lead-up to World War II. Nazi Germany was indeed a police state, using the SS and the Gestapo to assert control over the population from the 1930s until the end of the war.
During the period of Apartheid, the South African government maintained police state attributes such as banning people and organizations, arresting political prisoners, and maintaining segregated living communities and restricting movement and access.
Augusto Pinochet's Chile was a police state exhibiting "repression of public liberties, the elimination of political exchange, limiting freedom of speech, abolishing the right to strike, freezing wages."
The Republic of Cuba, under president (and later nationalist dictator) Fulgencio Batista, was a dictatorial police state until his overthrow at the end of the Cuban Revolution in 1959 and the rise to power of Fidel Castro and his communist regime. 
The region of North Korea has long had elements of a police state, from the Juche -style Silla kingdom, to the imposition of a fascist police state by the Japanese, to the police state imposed and maintained by the Kim family. Paris-based Reporters Without Borders has ranked North Korea last or second last in their test of press freedom since the index's introduction, stating that the ruling Kim family control all of the media. 
Fictional police states
Fictional police states have been featured in a number of media ranging from novels to films to video games. George Orwell's 1984 has been described as "the definitive fictional treatment of a police state, which has also influenced contemporary usage of the term".
- Amnesty international, 2005 — annual report on human rights violations.
- Council for Secular Humanism article describing attributes of police states
- David Mery, September 22, 2005; The Guardian — example of "police state" defined in a modern context.
- Police State USA — a continuously updated multi-contributor site with news articles that document police brutality in the United States
- The Rutherford Institute — a non-profit civil liberties organization based in Charlottesville, Virginia. Founder and president John W. Whitehead believes that the U.S. is an "emerging" police state.
- Tipton, Elise K. (2013-12-17). The Japanese Police State: Tokko in Interwar Japan. A&C Black. pp. 14–. ISBN 9781780939742. Retrieved 5 September 2014.
- A Dictionary of World History, Market House Books, Oxford University Press, 2000.
- The Police State, Chapman, B., Government and Opposition, Vol.3:4, 428–440, (2007). Accessible online at http://www3.interscience.wiley.com/journal/119912141/abstract, retrieved 15 August 2008.
- Oxford English Dictionary, Third edition, January 2009; online version November 2010. <http://www.oed.com:80/Entry/146832>; accessed 19 January 2011.
- The New Police Science: The Police Power in Domestic and International edited by Markus Dubber, Mariana Valverde
- Police State (Key Concepts in Political Science), Brian Chapman, Macmillan, 1971.
- "Police Checkpoints on the Information Highway", Computer underground Digest, Volume 6 : Issue 72 (14 August 1994), ISSN 1004-042X, "The so-called 'electronic frontier' is quickly turning into an electronic police state."
- The Electronic Police State: 2008 National Rankings, by Jonathan Logan, Cryptohippie USA.
- JOHN O. KOEHLER. "Stasi: The Untold Story of the East German Secret Police". New York Times. Retrieved March 22, 2014.
- "SS Police State". U.S. Holocaust Museum. Retrieved March 22, 2014.
- Cooper, Frederick (2002-10-10). Africa Since 1940: The Past of the Present. Cambridge University Press. pp. 149–. ISBN 9780521776004. Retrieved 22 March 2014.
- Zwier, Paul J. (2013-04-22). Principled Negotiation and Mediation in the International Arena: Talking with Evil. Cambridge University Press. pp. 235–. ISBN 9781107026872. Retrieved 22 March 2014.
- Casanova, Pablo González (1993-01-01). Latin America Today. United Nations University Press. pp. 233–. ISBN 9789280808193. Retrieved 22 March 2014.
- Candelaria, Cordelia; García, Peter J.; Aldama, Arturo J. (2004). Encyclopedia of Latino Popular Culture. Greenwood Publishing Group. pp. 120–. ISBN 9780313332104. Retrieved 27 March 2014.
- Bailey, Helen Miller; Cruz, Frank H. (1972-01-01). The Latin Americans: Past and Present. Houghton Mifflin. ISBN 9780395133736. Retrieved 27 March 2014.
- Novas, Himilce (2007-11-27). Everything You Need to Know About Latino History: 2008 Edition. Penguin Group US. pp. 225–. ISBN 9781101213537. Retrieved 27 March 2014.
- Becker, Jasper (2005-05-01). Rogue Regime : Kim Jong Il and the Looming Threat of North Korea: Kim Jong Il and the Looming Threat of North Korea. Oxford University Press. pp. 74–. ISBN 9780198038108. Retrieved 22 March 2014.
- Hixson, Walter L. (2008). The Myth of American Diplomacy: National Identity and U.S. Foreign Policy. Yale University Press. pp. 179–. ISBN 9780300150131. Retrieved 22 March 2014.
- "North Korea Rated World's Worst Violator of Press Freedom". America.gov. 2006-10-25. Retrieved 2008-07-23.
- North Korea still one of the world's most repressive media environments
- The Encyclopedia of Police Science  Volume 1 edited by Jack R. Greene
- The Rutherford Institute John W. Whitehead to Speak to Senior Statesmen of Virginia on the Emerging American Police State and What 2014 Holds in Store for Our Freedoms