These highly specialized assessments look at infrastructure from the perspective of a terrorist. Using both online resources as well as site visits, terrorism risk assessments examine the desirability of the asset as a potential terrorist target, what the likely aims would be were a group to target the asset and the steps hostile actors most likely would take to prepare for an attack. Terrorism risk assessments identify vulnerabilities that can be exploited by terrorists to enable owners and operators to appropriately mitigate them, and they alert on-site personnel to the signs of pre-operational surveillance and planning to enable them to detect and thwart an attack before it occurs.