A recent article in Security-Focus described the fact that several U.S. government buildings in Washington DC could no longer be clearly seen by people using MapQuest's aerial photo database. In addition, the photos of these buildings were altered at the Web sites wherein they are posted at the request of the U.S. Secret Service. This is an example of spatial information that was rendered unavailable after September 11, 2001. Spatial information has a variety of forms. Even before September 11, 2001, there were a number of reasons why government agencies withheld information from libraries and the public. In this article, the author discusses five of these reasons: (1) Data availability was limited because of the Cold War; (2) Federal legislation protecting certain types of natural and relict human features; (3) Cooperative Research and Development Agreements (CRADAs); (4) Exorbitant government information pricing; and (5) Threat of potential terrorism. In addition, the author discusses the events that happened after September 11, 2001 when data that had already been posted really started to disappear. Finally, the author mentions how a Homeland Security Working Group is moving toward solutions. (Contains 3 figures and 17 footnotes.)