Electronic devices can be used to track people, animals, vehicles, and virtually anything else that moves. Electronic tracking can be distinguished from electronic surveillance equipment in that the location of the subject is the primary goal of tracking. Surveillance involves actually seeing or hearing the subject. Prior to electronics, tracking meant following the trail of evidence left behind by the subject: his or her scent, fingerprints, footprints, etc.

Modern electronic tracking began in earnest with the advent of radar during World War II. American Heddy Lamarr, better known as a movie star, patented a device to track and guide torpedoes. The torpedoes emitted a radio signal that was received back at the submarine that launched it. At the time, Lamarr's invention was ignored, but gained a great deal of interest after the war.

During the 1950s, the first man-made satellites were launched into space, allowing the expansion of electronic tracking devices. With this technology, the subject transmits its signal to a receiver in the satellite. The satellite, maintaining a geosynchronous orbit with a fixed coordinate on the ground, can track the subject anywhere on the planet. In the 1960s, the U.S. military proposed a vast global positioning system (GPS) network. This technology was initially designed to track nuclear missiles, but soon found numerous civilian applications.

By the mid-1980s electronic tracking devices were being used in a variety of ways. Convicts serving their sentences under house arrest in some jurisdictions have been fitted with monitoring anklets that contain transmitters. A receiver is planted inside the subject's telephone, and the signal is forwarded to a central computer. If the wearer strays too far from home, the signal is interrupted and the authorities are notified. More advanced systems allow the prisoner to travel only to particular destinations (such as a job). Rental car companies use electronic tracking devices in their vehicles as well. In addition to security, drivers can use the devices with onboard computerized maps to navigate unfamiliar areas. Electronic tracking devices have many other such uses, but have also raised concerns regarding privacy rights since continuous monitoring from space is now possible.