Despite last year's Supreme Court ruling that vehicle tracking constitutes a search, and thus requires a warrant, the Obama administration instructs agencies to continue to attach GPS tracking devices to the vehicles of US Citizens illegally.
http://www.wired.com/threatlevel/2013/03/gps-warrant-requirement/
Details on last years ruling that forces such tracking to be considered search and seizure:
http://www.wired.com/threatlevel/2012/01/scotus-gps-ruling/
http://www.wired.com/threatlevel/2013/03/gps-warrant-requirement/
Details on last years ruling that forces such tracking to be considered search and seizure:
http://www.wired.com/threatlevel/2012/01/scotus-gps-ruling/