[2] To the extent that punitive methods often involve incarceration, thereby preventing further crimes being committed by the individual, they can also be considered preventive;[3] the penological theory justifying this is incapacitation.
Michael L. Rich further defines as the "perfect preventive state" a situation in which targeted criminal conduct is made impossible by the mandates of government.
[4] There is a wide scope for the use of preventive methods, which is constantly increased by developing technologies; in-vehicle technology responding to a user's blood alcohol level (BAL) and restricting use; restrictive measures in the infrastructure of the World Wide Web (i.e., preventing users' being able to illegally download music).
[4] Several countries have deployed them as a means of anti-terrorism in the wake of terrorist attacks; preventive measures can include intelligence gathering, detention and interrogation.
[6] Preventive policies have raised serious concerns about liberty and freedom in modern democracies, and continue to generate debate.