If you do think a fine is unfair you can contest it pretty easily though. Most people who do this are incorrect and end up still paying the fine (because the were actually speeding) but in cases where the cameras are wrong or if there was something special going on the fine is usually thrown out the window.

At least that's my observation here in .nl. Obviously the cameras aren't always right, but the people I see complaining the most are also the ones that drive >10% over the speed limit by default anyway.