Social networking sites and other examples of online social spaces have greatly expanded their members' opportunities for self expression and social interaction, while creating significant challenges for online privacy management. Within offline social spaces, privacy management is an active part of everyday life, influencing where, when and to whom we decide to reveal private information. Just as technology mediation changes the nature of communication, so will technology mediation of social interaction change the nature of privacy management. This paper describes work done to establish reliable measures of online privacy management based on Adaptive Structuration Theory (AST). AST provides a framework for modeling the use of technology in a social setting, includes a way to measure appropriation, the process by which users adapt and adopt technology. These measures have been used to examine appropriation patterns within two US based social networking sites (Facebook and MySpace), and StudiVZ, a site based in Germany. The measures demonstrated an acceptable level of reliability, and the results exposed differences in the privacy management strategies employed by the members of these sites. The result of this research is the establishment of theory based measures that can be used to capture the structure of online privacy management.