I understand your point, however, I would not call what they were doing "fun". It is perverted and it would not surprise me one bit to find out these people are child molesters or view child porn, etc....
well .. this is holland. They are really famous for tollerance against loonies.
Actually I like their attitude - obviously they take care if you end up struggling in a van. Can you say so for every place in the US ?
No really - generally spoken you will run across looneys their every single moment and if you tell people you are offended by someones 'wierd behaviour' they will ask you to look otherways - but honestly, life is really safe and easy in the netherlands.
Just more - strange.