20 bucks says this guy frequented 4chan. Probably /co/, /pol/, & /k/.
http://www.abc15.com/news/crime/update-armed-man-arrested-at-phx-comicon-after-struggling-with-police
http://www.abc15.com/news/crime/update-armed-man-arrested-at-phx-comicon-after-struggling-with-police