i realize you can't always say what you think, but for me that only holds true in real life.
This is the thing that's fundamentally wrong with internet forums. And I don't mean you or GW, I mean internet. Of course the social situation is different online and that old "don't say anything you wouldn't say face to face" thing is bullshit, but that has nothing to do with people completely abandoning all sense of social conduct,
discretion and basic manners. The rules are different, but that doesn't mean there aren't any rules. Anonymity is one of the main culprits here, give people real names and they immediately shape up. That effect is actually amazingly strong, it can do wonders when Marge becomes Markus Hauru, even though you're still complete strangers.
This hasn't much to do with the original comment on dutch girls anymore, I've heard people say lots of stuff like that outside internet. You just hit the nail on the head with that sentence I quoted.
It's funny seeing peoples behaviour change on the net once they meet the nickname (or even the real name) in person. Even those who behave politely and emphatically. People continuously say stuff you consider stupid or you think that they're wrong in something and normally you let most of it pass. It may change your view of the person and your behaviour towards them but you don't immediately stand up and declare "That, is incorrect! I want to debate this!". Like what I'm doing here.