Insider threat is a well-known phenomenon that is considered by most to be the greatest threat to any information security environment. Access control measures attempt to mitigate much of this through physical (hardware) and software-based means.
In the case of environments where industrial control systems (ICS) are prevalent, this threat is enhanced by the unique capability in such situations to cause physical harm to employees, the processes they manage and the plant itself. In addition, potentially damaging events to the environment and the population.