Vehicle tracking devices use GPS to transmit a vehicle's location to an observer. The device may record a vehicle's movements or broadcast them in real time. Before GPS, vehicle tracking devices used radio triangulation and a system from Motorola that was based on the United States Coast Guard's navigation technology. In January 2012, the Supreme Court ruled that law enforcement's use of GPS trackers constitutes a search, so police require a warrant before attaching a tracking device.
Private investigators occasionally use tracking devices to monitor people suspected of cheating on their partners. In the United States, laws concerning tracking private individuals vary from state to state. If an individual has not consented to being tracked, some states punish the person carrying out the tracking with a prison sentence.
Companies such as TomTom offer tracking software along with the devices themselves. Offices that need to keep track of fleets of vehicles can use TomTom's online WEBFLEET application to check each vehicle's location with minute-by-minute updates. TomTom can also provide offices with information on each vehicle's acceleration and over-steering, which allows managers to monitor their drivers' behavior.
Tracking devices are available from BrickHouseSecurity.com and SpyTechs.com. The advanced trackers allow users to monitor vehicle movements in real time on tablets or smartphones.