[m0dem]

I know Wikipedia isn't the most reliable source, but:
https://en.wikipedia.org/wiki/2011_Norway_attacks

Read about the preparations. A regular sane person does not just lose it and make plans this elaborate. Like with any mass killing, this guy was sick in the head and everything was premeditated. I suppose we should ban fertilizer as well.

Wow, that was a really complex plan.

I found this interesting:

Breivik's manifesto says that he made use of the video game Call of Duty: Modern Warfare 2 as a training aid while using World of Warcraft as a cover for his extended period of isolation