Electronic monitoring in the United States

Electronic monitoring or electronic incarceration (e-carceration) is state use of digital technology to monitor, track and constrain an individual's movements outside of a prison, jail or detention center. Common examples of electronic monitoring of individuals under pre-trial or immigrant detention, house arrest, on probation or parole include: GPS wrist and ankle monitors, cellphones with biometric security systems, ignition interlock devices and automated probation check-in centers or kiosks.

Source: Wikipedia — Electronic monitoring in the United States (CC BY-SA 4.0)