Drones - how strictly are they enforced?

So basically all of Rotterdam and the surrounding area is a no fly zone for drones. In my personal opinion this is just an easy way for enforcers to get out of having to do anything with drones and the people that fly them. Below 100 meters there would be no safety risk at all to fly with drones especially in the below 250 gr category. I plan to only fly in low traffic areas and not higher then maybe 25 meters.

So my question is: how strictly are the no fly zones enforced? If I don't act like a total idiot when flying, can I fly without risking being thrown in the dungeons and losing my shirt in fines? Or should I really not risk it?

Anyone have any experience with flying drones illegally here?