Top Secret America
The Washington Post's Top Secret America interactive map shows the locations of the "Top Secret America created since 9/11 that is hidden from public view."
The Post argues that since 9/11 America has been building a secret privatised national security network, a network of contractors who "are obligated to shareholders rather than the public interest".
The Washington Post's Google Map shows over 7,000 private-sector company locations involved in top-secret work. It is possible to search the map by location. It is also possible to select to view 'government work locations' on the map and 'company work locations'.
The map uses coloured circular map markers whose size reflects the number of companies / government agencies shown. For example, in the screenshot of Washington DC above, the blue areas represent company locations and the red government locations.