Insider attack and espionage on computer-based information is a major problem for business organizations and governments. Knowledge Management Systems (KMSs) are not exempt from this threat. Prior research presented the Congenial Access Control Model (CAC), a relationship-based access control model, as a better access control method for KMS because it reduces the adverse effect of stringent security measures on the usability of KMSs. However, the CAC model, like other models, e.g., Role Based Access Control (RBAC), Time-Based Access Control (TBAC), and History Based Access Control (HBAC), does not provide adequate protection against privilege abuse by authorized users that can lead to industrial espionage. In this paper, the authors provide an Espionage Prevention Model (EP) that uses Semantic web-based annotations on knowledge assets to store relevant information and compares it to the Friend-Of-A-Friend (FOAF) data of the potential recipient of the resource. It can serve as an additional layer to previous access control models, preferably the Congenial Access Control (CAC) model.