Automated License Plate Recognition [wiki] or ALPR technology is not exactly new: it was invented in 1976 and is currently used to for traffic congestion control in London.
Canada is testing out a portable system using a specially outfitted police cars: cameras on the outside of the car will automatically scan license plates of cars as the policeman drives - and the computer will ping if it finds a match of the license plate with a hit from databases of stolen vehicles, outstanding warrants, etc.
Predictably, critics are accusing the system as being Big Brother-worthy. Oh, and see if you can find the "irony" in the video clip. Hint: it's a guy driving.
Hit play or go to Link [YouTube] - Thanks matthew!