High policing is a form of intelligence-led policing that serves to protect the national government or a conglomerate of national governments from internal threats; that is, any policing operations integrated into domestic intelligence gathering, national security, or international security operations for the purpose of protecting government.
The primary tool of high policing is intelligence, which is derived from both human ("Humint") and technological sources.
There is a tendency, even in democratic countries, for high policing organizations to abuse their powers or even to operate outside the law because many organizations involved in high policing are granted extensive legal powers, including immunity from prosecution for acts that are criminal under normal circumstances.
In some countries, for example, high-policing organizations regularly engage in actions of dubious legality, such as arbitrarily arresting and detaining people without charge, without legal representation, and without means of communication; some high-policing forces also engage in torture.
In the worst cases, high policing becomes a substitute for the whole criminal justice system: suspects are arrested, tried, convicted, and sentenced entirely by a national security agency, usually very expeditiously and in complete secrecy, as is the case in police states.