Leon Gray 
Global Positioning System: Who’s Tracking You? [PDF ebook] 

We usually think of GPS (Global Positioning System) as a good thing, especially if we’re using it to find our way from place to place. GPS satellites, radio signals, and receivers work together to pinpoint our location and get us to our destination. Hikers, bicyclists, and even golfers are finding ways to use GPS to improve their athletic experiences. The military installs GPS in many kinds of equipment, vehicles, and weaponry. GPS has surprising applications as well, such as tracking animals for conservation efforts. But many people are suspicious of this technology, especially when it’s used to locate them without their consent. Many aspects of the GPS debate are explained, giving readers the ability decide for themselves where, when, and how satellite positioning should be used.