So the boy was half Iranian, born in Germany - or then not. Anyhow, he apparently had been bullied and it probably had become worse because of Isis. So, aided by the plethora of information and inspiration, he snapped.
I've been bullied because of my descent being half German. Even after some 25 years after the war the Nazi antipathy legitimated that, even amongst primary school kids. Even my teacher told me that words don't hurt. That's what made me the man I now am. Who knows, with today's rapidness of information and all the Internet stuff I might have snapped, too.