Data surveillance is the systematic use of personal data systems in the investigation or monitoring of the actions or communications of one or more persons. This collection of papers was the basis for a supplication under Rule 28 of the ANU's Degree of Doctor of Philosophy Rules. The papers develop a body of theory that explains the nature, applications and impacts of the data processing technologies that support the investigation or monitoring of individuals and populations. Literature review and analysis is supplemented by reports of field work undertaken in both the United States and Australia, which tested the body of theory, and enabled it to be articulated. The research programme established a firm theoretical foundation for further work. It provided insights into appropriate research methods, and delivered not only empirically-based descriptive and explanatory data, but also evaluative information relevant to policy-decisions. The body of work as a whole provides a basis on which more mature research work is able to build.