Governments are now reaching a critical point in the use of electronic monitoring as a means of reducing costs and improving the effectiveness of corrections. There are three main rationales behind the use of electronic monitoring. Electronic monitoring can be used to ensure that the individual remains in a designated place; an individual does not enter proscribed areas, or approach particular people, such as complainants, potential victims, or co-offenders; and authorities can continuously track a person, without actually restricting their movements. There are a number of technologies available that can aid with the detention, restriction, or surveillance of individuals within the criminal justice system. Most involve some kind of device that is locked onto the subject’s wrist or ankle with tamper-proof elements to prevent removal. In passive systems, wearers are periodically contacted by telephone to ensure that they are where they are supposed to be. Active systems use a device worn by the individual that continuously emits a signal. A corresponding device in the person’s home relays the signal to a monitoring station. If the wearer strays too far from home or breaks the device, the authorities are alerted. Global Positioning Systems (GPS) consist of three components: satellites, a network of ground stations, and mobile user devices. Measuring the user’s distance from three different satellites identifies the user’s location. There are three stages at which electronic monitoring may be used: pre-trial, at sentencing, and postprison. One of the major advantages of electronic monitoring is the possibility of reduced prison populations. Another is the possibility of improving rehabilitation and reintegration of offenders. A disadvantage of electronic monitoring is the lack of incapacitation. The use of electronic monitoring raises a number of ethical, legal, and practical issues. The surveillance potential creates concerns of overregulation and infringement of human rights. The necessity for ensuring informed consent of those chosen to be subject to monitoring should be guaranteed and effective procedures established to deal with unethical or illegal practices. 34 references