Well you put your thread in what is undoubtedly the correct category. I went with "World/Foreign" on the 0.0001% chance it was something other than the Aloha Snackbar brigade.
Good thing Merkel spearheaded the whole "let millions come pouring directly into the heart of Europe" campaign, eh? She and France's Hollande have both made comments to the effect of "If you don't like it, get out of (France / Germany)"
Watch it turn out that the perpetrators of this attack were among the recent horde to come into Europe.