Management professor Lucas Introna, who specializes in workplace surveillance issues, said GPS tracking provided just enough information to breed discontent.
"In an office or a factory situation, a manager who might walk by has access to a whole range of situational information," said Introna, who teaches at Lancaster University in Britain. "But when a worker far away knows that every move they make is monitored by someone -- without information about just what they are doing -- it takes on a punitive sense."
Kinney didn't disagree. "The guys hate it," he conceded, even though the worker caught at home was able to show that he had gone to pick up materials needed for the job.
GPS, which uses a network of orbiting satellites to fix precise locations on Earth, was developed for the military. But as soon as the first satellite in the system was turned on in 1978, academics were testing its capabilities. By the early 1980s surveyors were using GPS in their work.
GPS has proved to be one of the most popular consumer uses of space technology. So far this year, nearly 3.9 million new cars came with factory-installed GPS navigation systems, according to research company CMS Worldwide. In 2008, that number is forecast to reach 6.5 million.
Hand-held GPS units for hikers, bicyclists and runners have steadily fallen in price and are now available for about $100.
Satellite tracking for the non-military market got its first big boost in 1988 when then-fledgling Qualcomm Inc. of San Diego introduced a system that allowed fleet managers to spot where their vehicles were anywhere in the country.
Consumer GPS tracking gear was soon to follow, popping up in shops and eventually on websites that often had "spy" as part of their names.
"I would say that 60% of my sales are to women who say, 'I think my husband is cheating on me,' " said Greg Shields of Cincinnati, who operates the Spygear Store on the Web and sells a $500 unit designed to be magnetically attached to the bottom of a vehicle. "The rest are men who want to track employees."
The unit is removed after several days and plugged into a personal computer to produce a map that can be zoomed down to the street level to show not only where the vehicle has been but also its speed and all starts and stops. Shields also sells a $1,200 device that sends the signals back to a personal computer for real-time tracking.
