The geographic information system (GIS) literature has contributed little to describing technical measures that are designed to protect privacy in a GIS environment. Instead, it has recognized and commented on a variety of ways in which knowledge of the locations of individuals can compromise their privacy and make it difficult to protect the confidentiality of records of individuals in a GIS environment.1-7 VanWey et al. discussed conflicts between preserving social-spatial data linkages and confidentiality protection.8