Over the past decade, developers have made enormous strides in access to and visualization of public domain geospatial data, as evidenced by online tools such as Google Earth, Google Maps, ESRI’s ArcGIS Explorer, Microsoft’s Virtual Earth, or NASA's World Wind. The distribution of spatial data, particularly high-resolution aerial photography, may raise issues of privacy. Geographic Information Systems (GIS) are powerful integrating technologies capable of bringing together information from a variety of sources. This includes data volunteered by members of the public, such as the location of favorite restaurants, as well as more sensitive topics including public health. The analytical potential of linking data sets like these is great and can provide important services (such as supporting disaster management efforts); however, confidentiality and privacy issues are also a concern.

Local, state, and federal government entities are adopting and implementing GIS applications to support decision making and make government more efficient. In doing so, many of these organizations are publishing digital geospatial information and applications online. These GIS Web-based services are designed to make the data and tools more accessible to the general public. However, there is an increasing perception that these applications may have unintended consequences related to privacy.

It should be noted that the vast majority of information provided through Web-mapping services like Googe Earth is public information (imagery from NASA and USGS, for example). This information is the same information that stakeholders would obtain by visiting a local government agency (zoning, assessor’s office, planning, NRCS, USGS, etc.). Web-mapping services simply make accessing public information easier than in the past. It is this ease of access and use that has made the privacy question much larger than it was in the past.