...of Muslims in Europe. Not that moral degenerates like Daesh care, but I'm convinced we're witnessing the beginnings of a sea change over there, and the possible outcome for Muslims in Europe could be horrifying. Humans all over are, collectively, prone to some pretty extreme swings of the pendulum. What some may have chosen to see as a permanent change in pan-European culture towards acceptance of multiculturalism following the atrocities if the Fascist era is not as fully inculcated in modern Europeans as they may think. I'd argue that it's instead a thin veneer that each generational cycle reduces instead of bolstering (because it's just that much further removed from the past and that much closer to things like these attacks). It's a form of bigotry: "Oh, that could never happen again to Europeans! They've become much too civilized!" Don't believe it.
If the governments in the most affected countries don't find these criminals and act in a demonstrably effective manner to curb future repetition, those governments will fall, to be replaced by far more right-wing parties. The same for further attacks like Paris. And anyone that doesn't think that a shift to the right greases the skids toward atrocities is horribly naive about both history and mob psychology.
Frankly, if those potential atrocities only caught people like those perpetrators of attacks on women or terrorists, I wouldn't lose a lot of sleep over it. But that's not how it would go down, is it? Mobs (even those comprised of legislators...) aren't known for being able to discriminate between the guilty and the innocent with any accuracy.