500 euros fine! that is oppressive! I know they say that "it's to protect the little nature we have" sure, they always give stories like that.
anyway, it's not stopping some of my NZ friends who are currently touring the netherlands (and making a youtube series about it) https://www.youtube.com/watch?v=eaCeRT-HaUU This is the guy who taught me you can just camp everywhere "no camping" signs be damned (way back in 2003)
of course, remember to follow Deuteronomy 23:12-14
Thou shalt have a place also without the camp, whither thou shalt go forth abroad: And thou shalt have a paddle upon thy weapon; and it shall be, when thou wilt ease thyself abroad, thou shalt dig therewith, and shalt turn back and cover that which cometh from thee: For the Lord thy God walketh in the midst of thy camp, and if he stepeth in a poop thou will know he is Lord when he layeth his vengance upon thee