Some years ago there was a rash of deadly car crashes resulting from police pursuits, which prompted city officials to approve the purchase of a police helicopter with the understanding that such an investment would all but put an end to high-speed chases.
Recently, police in Los Angeles announced the adoption of yet another crimefighting tool with much the same promise, utilizing the same technology Tulsa voters approved funding for just last month.
A "dart-like device" is fired at a fleeing vehicle, which begins to transmit it's GPS location over the cellular network to police, who then locate the vehicle in much the same way they would locate a 911 caller.
StarChase, the system's manufacturer, says the platform is approved by the National Security Agency.
http://www.informationweek.com/hardware/showArticle.jhtml?articleID=178601965
http://abcnews.go.com/US/story?id=1576247