1) Inherent Limitations of the Web: The Web was initially designed to facilitate the search, retrieval, and presentation of text- and image-based information by means of Hypertext Markup Language (HTML) documents. It has limited capabilities for spatial database applications using vector data without enhancements that require development costs and efforts.
2) Inherent Limitations of Spatial Databases: Spatial databases are characteristically heterogeneous because they are constructed using.different database models, represented at different scales and with different cartographic and attribute classification schemes. The structural and semantic differences among spatial databases, together with the inadequacy of spatial metadata information have inhibited the potential applicability of Web-enabled spatial database systems.
3) Security and Privacy Concerns: Spatial data transmitted over the Internet are vulnerable to abuse and can be spied on relatively easily. Although encryption methods for text-based data are well developed and reliable for online transaction processing, encryption technology has apparently not been as well developed for spatial data. This limits the usability of Web-enabled applications, particularly when sensitive spatial data are involved or authenticity of the data being delivered is required.
4) Copyright Control and Liability of Abuse and Misuse: Many organizations are not willing to adopt a Web-enabled approach to spatial information because it is hard to control and retain the copyright of the data disseminated to end-users. Some organizations are also deterred by the increasing possibility of legal liability when spatial data are made easily obtainable by a large number of unknown end users who may abuse or misuse the data.
