GPS Tracking

GPS Tracking

GPS trackers enable the government to record your movements extensively. Using this information, officials can build a revealing portrait of your relationships, activities, values, and viewpoints.

What is it used for?: 

Small and easily hidden, GPS tracking devices allow the police to watch the movements of individuals with precision and stealth. In some investigations, police have secretly attached a GPS tracker to a suspect’s car for days or weeks at a time. The resulting data allows police to build a detailed picture of an individual’s life –  where you live, work, shop, and eat, when you leave in the morning and return home at night. It shows the government which organizations you belong to, and who you spend your time with. Many departments also use GPS trackers, embedded in ankle bracelets, to enforce house arrest and parole orders. Additionally, some police departments have begun using GPS to track their own officers’ movements. 


In the past, cost limited the ability of the police to follow people;  assigning officers to tail a suspect at all times is a serious investment of time and resources.  But the ease and low cost of attaching a GPS receiver to a person’s car changes matters. The GPS receivers police departments use can easily track your car for days or weeks. While the government has argued that this type of location tracking is no different from the old-fashioned tailing of suspects by detectives, in fact it is much more intrusive – like having a police officer in your back seat 24/7. Indeed, the U.S. Supreme Court has found that prolonged GPS tracking constitutes a search under the Fourth Amendment. The Third Circuit Court of Appeals recently ruled that investigators need a warrant for long-term GPS tracking. In 2003, the Washington State Supreme Court found that the state constitution requires police to get a warrant before attaching a GPS tracker to a suspect’s car.

How it Works: 

The U.S. military developed the Global Positioning System (GPS) in the 1970s to aid in navigation. Later, it opened the system for use by the global public.

  • GPS is a network of dozens of satellites in low orbit. It forms a pattern that ensures that four satellites are always “visible” to every point on earth.
  • GPS receivers intercept the signals emitted by these satellites. These signals contain information about the satellite’s position in the sky. By combining data from three or more satellites, the receiver can calculate its own location, a process called ‘trilateration.’
  • The GPS receivers used by police departments transmit their location data back to investigators. Investigators can monitor the movements of a suspect vehicle in real-time, or save the vehicle’s movement history for review later. By overlaying the location data and time stamps on a map, the police discover the places the vehicle has visited, the routes its driver took, even the speed at which he was driving.
How prevalent is it?: 

Law enforcement agencies have eagerly embraced GPS tracking. Investing in these devices has enabled investigators to save enormous amounts of staff time and resources. The FBI alone owns over 3,000 of them. 


Examples of Use

Related Civil Liberties Concerns: 

When government agencies consider acquiring and using surveillance systems, communities and their elected officials must both weigh the benefits against the costs to civil liberties and carefully craft policies and procedures that help to limit the negative effects that surveillance will have on fundamental rights.  For a useful list of considerations, please visit the recommendations page.