As a few people have said I think they can be very harsh with camera vans catching people who have unwittingly crept over the limit.
The laws are abit strict I think everyone brakes the law whilst however minor because there's so many driving laws Im surprised you allowed to adjust the volume on your stereo (in fact I bet there's a law for that)
Also some officers (because there not all bad lol) should set an example
I've seen police driving Mobile phone in hand and one driving with no hands on the wheel