Most of the time flying in France is so carefree you never want to go home but...
They have a branch of the police who tour around the airfields (in their own TB20s!!) and enforce the rules, naturally mainly on foreign pilots, because what is interdict for us is not usually interdict for them!
So long as your paperwork is squeaky clean they are fairly easy to deal with (only in French naturally!). However if there is anything wrong, your experiences with theFReanch judicial system are just starting.
I've bumped into those flying Gendarmes only twice - I guess they aren't many of them, but they take no prisoners.