Internal users continue to be the torn in system and security administrator's side. This is the case for many reasons. One, they have knowledge of the networking recourses. Two, they have credentials to access various systems on the network and third, most security controls defend against external entities as compared to internal users. According to the Computer Security Institute (CSI), approximately 80 percent of network misuse incidents originate from inside the network.
Security Administrators should apply the “Defense in Depth” security model when it comes to protecting the network. This mean network firewalls, IDS, HIDS, host-based firewalls, patch management, security policies and vulnerability scanning.