http://www.wired.com/threatlevel/2010/10/fbi-tracking-device...
http://www.wired.com/threatlevel/2010/10/fbi-tracking-device...
The FBI demanded the device back and she said no. Amazingly, that was the end of the story—until the Afifi story came out, and she decided to give Wired the tracker.
The interesting legal question (in addition to whether you need a warrant to do this sort of thing) is who owns something attached to your car?
If the tracking were completely legally sanctioned, I can't imagine that the trackee would have any claim to ownership over the device.
Alternatively they expect these to go missing and it's not worth the hassle to get them back.
1. Supreme Court rules that use of GPS tracking devices by law enforcement do not violate 4th Amendment.
2. Future court rulings find that tampering with GPS devices amounts to interfering with a police investigation.
3. Law enforcement starts planting GPS devices directly on persons, such as in a purse, or when miniaturized further, in wallets or attached to clothing. Maybe these devices only capture data "when in public areas" and are eventually declared legal.
4. Since they cannot be tampered with, police begin attaching wristbands to citizens stopped at routine traffic stops who they suspect of crimes.
Sounds far-fetched, but not when you consider the amount of surveillance that goes on already via cell phones and credit cards.
There are people walking around with government installed GPS bracelets right now: http://en.wikipedia.org/wiki/Ankle_monitor