Systems and methods for calculating threat scores for individuals within an organization or domain are provided. Aspects of the invention relate to computer-implemented methods that form a predictive threat rating for user accounts. In one implementation, a threat score representing a first time period may be calculated. The first threat score may be calculated from a quantification of a plurality of activity violations across a plurality of control groups. Weighting schemes may be applied to certain activities, controls, and/or user accounts. Further embodiments may be configured to consider additional indicators. Further aspects relate to apparatuses configured to execute methods for ranking individual user accounts. Certain embodiments may not block transmissions that violate predefine rules, however, indications of such improper transmission may be considered when constructing a threat rating.