It says that you have a significant enough population of so called "chavs". And it's not just Britain. The kids in America were more or less the same. Lots of built-up anger in both cases.
Looking at many of these pictures is a reminder that poverty is akin to a disease.
From the photo where the kids are hiding their face, I'd guess there's a better chance that they think it's the police or some other government department photographing them than it being an anti-Google sentiment.
I suppose though it may depend on how the car/vehicle itself is branded.
you see a google car approaching and start to think quickly, what to do? how to express yourself? and i think even a total nerdy 'high achiever' may come up with just showing his ass! :)))