Censorship of maps

Censorship of maps describes the way of handling the appearance of potential strategically important objects like military bases, power plants or transmitters towards their censorship on maps.The appearance of such objects on maps available to the public may be undesirable, so it is often attempted to conceal these locations on the map.

Censorship of maps was also used in former East Germany, especially for the areas near the border to West Germany in order to make attempts of defection more difficult. Censorship of maps is also applied by Google maps, where certain areas are greyed out or areas are purposely left out-dated with old imagery.

A variant of censorship of maps is putting in wrong high values. This can be important for predicting flooding. In World War I many German soldiers were killed in Belgium after their camps were flooded, even though the maps used by German military indicated the camp sites were not prone to flooding.

Censorship of maps is today still often applied, although it is less effective in the age of satellite picture services.

Similar cases
Lists of air traffic obstacles may not be published by many countries as many of them are strategically important (chimneys of power stations, radio masts, etc.)

Example

 * Hiding a VLF-transmitter of Russian Navy on a map. Compare with satellite image

Censorship of maps
Google Earth censors places that may be of special security concern. The following is a selection of such concerns:
 * The former Indian president APJ Abdul Kalam had expressed concern over the availability of high-resolution pictures of sensitive locations in India.
 * Indian Space Research Organization says that Google Earth poses a security threat to India and seeks dialogue with Google officials.
 * The South Korean government has expressed concern that the software offers images of the presidential palace and various military installations that could possibly be used by North Korea.
 * Operators of the Lucas Heights nuclear reactor in Sydney, Australia asked Google to censor high resolution pictures of the facility. However, they later withdrew the request.
 * The government of Israel also expressed concern over the availability of high-resolution pictures of sensitive locations in its territory, and applied pressure to have Israeli territory (and the Occupied Territories held by Israeli forces) appear in less clear detail.
 * The Vice President of the United States' residence (Naval Observatory) in Washington, DC has been pixelated, as has the Federal Gold Depository at Fort Knox.
 * From June of 2007 until January of 2009, downtown Washington, DC was shown using USGS aerial photography from the spring 2002, while the rest of the District of Columbia was shown using imagery from 2005.
 * In Morocco, the partially government owned Maroc Telecom Internet access provider banned all its subscribers for over two years for using Google Earth, but early in 2008 the censorship was removed.