in london you have to pay to drive your car in town. so to figure out who is driving around they surveil the entire city with cctv, and scan the video images for license plates, and then you have until 10pm that nite to pay your 16 dollar 'congestion charge' and if its not paid by 10:01 it goes up by another 200 bux... i know, i got pinched.
(and commercial vehicles have to pay 50 bux a day to drive around town!)
to help get videos of every nook and cranny of the city they use cctv-equipped smarties!
look close and you'll see the pole-mounted camera that pops up out of the roof.
when i was living in london id see one of these driving along queensway off of bayswater w2 all the time.
you'll see one is a 451.