- A tracking device designed to be inserted under the skin
could allow parents to keep tabs on their children, help courts track offenders
or make it easy to find lost hikers. But civil liberties campaigners are
already worried that the device might be abused.
- A prototype, dubbed the Digital Angel, is being developed
by Applied Digital Solutions of Florida, which has licensed the technology
from another company. "Although we're in the early developmental phase,
we expect to come forward with applications in many different areas, from
medical monitoring to law enforcement," says Richard Sullivan, ADS's
- The device contains a miniature global positioning system
(GPS) receiver, which uses tiny differences in timing signals from satellites
to calculate its position on Earth. The device can broadcast this information
to a local receiver. It gets its power from a piezoelectric device that
converts energy from a person's normal movements into electricity stored
in a small battery.
- The device, which will be the size of a small coin, would
be implanted just under the skin. Most of the time it would be inactive.
But a mechanical switch--or a timed series of muscular contractions--could
trigger it. Even a tune would do the trick. And instead of monitoring GPS
signals, the Digital Angel could be designed to monitor a person's vital
- It will also be possible to trigger the device remotely
using a coded radio signal, Sullivan says. This would be useful in the
case of a lost child or kidnap victim. And the authorities could activate
the Digital Angel to track down a prisoner on the run.
- Sullivan says his company will have a prototype ready
by the end of 2000. But others are sceptical because the technology for
a piezoelectric power supply is in its infancy. "You should never
say 'never' in today's technological age. But the power management technology
we have will not support something like this in the short range,"
says Ron Bishop, technology vice-president for SOS Wireless Telecommunications,
a company in Irvine, California, that sells cellphones designed for emergency
use. "I think you could make the parts small enough. But you're going
to have to carry around a 12-volt car battery."
- For civil liberties groups, that might be a good thing.
"This kind of stuff has enormous potential for abuse by the authorities,
or by anyone who can break into the information," says Emily Whitfield,
a spokeswoman for the American Civil Liberties Union. She worries that
the devices could become widespread, allowing governments to monitor their
citizens. And she speculates that criminals could crack the codes needed
to activate and use the devices, allowing them to pinpoint, say, potential