Tensions drive out Dutch
This has a very disturbing analogy to ghettosation, where the middle class leave a neighbourhood once they get the impression it is going south with undesirable elements. This is, of course, a self fulfilling prophecy where the trickle eventually becomes a flood and you have the creation of a new ghetto with the immigrants (generally) taking over the place.
This is not necessarily a bad thing theoratically if one takes a longer term view because it eventually corrects itself (see gentrification, Soho being a particular good example) but there are very distinct problems with such a scenario. Most obviously, alot of the ills you hear about ghettos do come through just because. Most of them are looked down upon and under privilleged (hence the middle class disappearance) and this becomes a vicious spiral when the neighbourhood goes 'bad'.
It's a chicken and egg thing. You do get an insular society/culture that doesn't mix much and this in turn makes the others less trusting or willing to mix with them and so on and so forth. The area does get poorer and depressed simply because the people who move there tend to be poor and underskilled. And unless the government steps in to do something about it it is unlikely things will change, see Britian and France. But at the same time, helping the 'immigrants' is a politically suicidal move, feeding fears that these immigrants are useless and feed from the 'real' taxpayers (both assertions not true in the US and generally so in Europe)
But what's truely disturbing about this is that it's affecting a nation and not a particular region. The problem doesn't seem very bad right now but the impression that people get could fuel the rise of right wing anti-immigrant extremist parties (remember that Pim guy?).
But at the end of the day, this is a case study of tolerance growing into intolerance and is something we ought to be mindful of. I will readily admit, that it lends great credence that somethings should be heavily censored i.e. religion and race so we don't see a return to the racial tensions of the 1960s. But I think we need to be careful before we draw such a broad proposition. Nations like France and Germany and even Britian face such similar pressures despite their varying attitutes towards discussions or race and religion (including hate speech and crime). And the US is a fine example of how rabid speeches on race and religion does not necessarily cause riots in the street (see how far L.A. has come since the Rodney King incident).
On a last parting note. In the finals of the NUS Challenge Shield, 10 young but very bright and mature JC debaters had to debate on race. You could tell they had never given it any thought. Good thing or bad will be up for history to decide.