I was watching some stupid show called 'parking wars'
Part of the show is parking enforcement in Jersey who go around and put boots on cars that have over 5 outstanding parking tickets.
The way they do it, they have a camera on the top of their van, and it scans license plates of parked cars for a violation. All the meter maids have to do is drive up and down the street until the computer makes a noise.
Fast forward 10 years and automatic license plate scanning will cross reference your facebook and google music to rank your mood and likelihood for violence today.