Of course you can be tracked by your cell phone since it is a transmitter but since most handheld GPS units are only receivers which work by triangulating transmitted signals from satelites and do not transmit any signals`(see: www.howstuffworks.com/gps.htm ) I don't think you could be tracked by most GPS units. Maybe these were special GPS units with transmitters (like On Star) so Public Works could keep track of their vehicles.

Also the news media has been known to lie. I remember back in the 1980s the Dallas newspaper has a story about a cop who got shot and they said the bullet was stopped by and ink pen and note pad. They showed a fake photo of the pen and note pad hit by the bullet. But the truth was that the bullet was stopped by a kevlar vest and they lied not wanting the criminals to know about kevlar vests and to go for head shots next time.