Disturbed about the future, and escalation, mostly. They all seem to send out these broad signals no one ever pays attention to, they act on their fantasies, and in the end get at least some of the notoriety they were seeking in the first place. And the various manifestos get viewed/read/listened to over and over. They get to spread their seed. So it feels like they ultimately end up inspiring some other sick mind to emulate their act, and that it's just a constant, inevitable spiral of darkness.