Perimeter Control

To Prevent Something from Happening

Premises that are considered dangerous or hazardous, for example, nuclear and chemical plants and airports, have permanent physical perimeter controls consisting of fences and other barriers to prevent unauthorized people from gaining entry and either harming themselves or causing mischief; so, too, do iconic buildings, government offices, and military and law enforcement premises. Electronic perimeter controls are set up to prevent cyber crime and cyber warfare or the “mischief-making” hacker from entering computers and ancillary programs, and organizations should seek advice from computer security experts on the requirements for ensuring the safety of their information and programs.

Hotels and places in which crowds gather—for example, shopping centers—where acts of terrorism may be anticipated are likely to have one or more perimeter controls on either a temporary or permanent basis, to deter such attacks. The outer perimeter control may be some distance from the target, where vehicles are checked, while the inner control could well be at the entrance to the potential target. In such cases, the outer control may be supported by physical barriers, such as fencing and gates, and even immovable concrete blocks. Both perimeter controls may be supported by closed circuit television and other technical measures such as intruder detection systems. Although in some cases such controls may be manned by law enforcement officers, generally, if the target is privately owned, they will be provided by private security companies.

Perimeter controls are often used to prevent protesters from reaching the target of their protest. For instance, since the rise of the antiglobalization movement, fences, backed by law [Page 724]enforcement officers, have been built around a number of meeting places for the G8 and G20 Groups, the World Trade Organization (WTO), the International Monetary Fund (IMF), and the World Bank. Similarly, in industrial disputes, particularly when the organization that is the subject of the dispute is still operating, law enforcement officers may implement a cordon to prevent those on strike from accessing the premises.

When a counterprotest is mounted as part of a community's response to a demonstration, for example, when antifascist groups meet in opposition to a meeting being held by extreme right-wing groups, it may be necessary for law enforcement agencies to place perimeter controls or cordons around one or both groups in order to prevent clashes. These perimeter controls normally consist of law enforcement officers and are sometimes controversial, depending on how long people are detained within the cordons.

To Aid Recovery after a Crisis

In the event of many crises—for example, acts of terrorism, outbreaks of infectious diseases, riots, industrial accidents, fires, earthquakes, and weather-related events such as hurricanes and tornadoes—it is essential that one or more of the emergency services gain control of the affected area as quickly as possible in order to bring the crisis under control and aid recovery. An important aspect of control is the introduction of perimeter controls. During the early stages, particularly if people have been killed or injured or are trapped, the initial response is invariably provided by the community itself but, as soon as the emergency services are present in sufficient numbers, the public may be physically excluded because (1) they may hinder the response and recovery and (2) additional people may become victims, particularly if the location of the crisis is hazardous or the crisis is ongoing.

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