Camilla Ragfors in The Guardian:
I understand how a man like Anders Behring Breivik fed the flames of his hatred, even if that was not the only reason for his terrible act of terrorism, because I was, for a while, his friend on Facebook.
I joined the Sweden Democrats many years ago. It wasn't because I was a nationalist, or terrified of Muslims. There were two reasons: one was pure and simple curiosity; the other was that I was interested to see how democracy works. I had soon had enough, not because the rest of the world hated me for being a member, but because of all the hate which came my way from people who saw the SD as God's solution to all the world's problems. I had never before come across such hatred.
One day I had a friend request on Facebook from Anders Breivik. There wasn't anything odd about that: when I was a member of SD I was magnetically attractive to everyone who called himself a nationalist: both those for whom it was a game, and the real extremists. Those were, in fact, the people who drove me away from the party. A machine of hate propaganda pumped through my feed on Facebook. There were YouTube clips of massacre victims, demands that all the “fucking niggers” should get out of the country, and far more horrible things.
I reacted by backing away. But for many other people who are weak, or feel bad for some reason, this stream was something to drink from.