Security and surveillance have featured heavily in film over the years. Their depiction has provided a platform for debate about appropriate levels of surveillance and has provided tangible illustrations of surveillance theory. Films have addressed the development of surveillance technology and the practice of monitoring citizens in the name of national security, portraying surveillance as both a necessary tool and at times a threat to liberty. The use of surveillance technology has been a controversial practice, often debated as an issue of civil liberty and potentially an invasion of privacy. How much surveillance is too much or too little is often debated in relation to serious threats to society, such as terrorist attacks and organized crime. In addressing these issues, films often illustrate surveillance theory in practice, providing useful insight into the benefits and drawbacks of particular theoretical perspectives on the use of surveillance. Concepts like social control, discipline/punishment of people who break the law, and convincing people to follow the rules are often inherent in the storylines of films on surveillance. A key idea in the study of surveillance is the concept of a panopticon. Originally, a panopticon was an architectural design for a prison that placed a guard in a well at the center of a prison, with inmates arranged around them. The guard could observe the prisoners at all times and the prisoners lived with a sense that they were constantly under surveillance. The design aimed to improve the security and efficiency of the prison. In the 1970s, Foucault applied the concept of a panopticon to society as a whole, arguing that the state acts as the prison guard and the public are the prisoners who are controlled by the belief that they are under constant surveillance. This idea has been influential in the study of surveillance, and the image of a central protagonist who monitors others with and without their awareness appears in several films from the 1970s onward. The film adaptation of 1984 often serves as an example of the threat of surveillance by the state. Equally, films like The Conversation and Enemy of the State have commented on the threat of covert acts of surveillance by small elites.