"Racism is low-hanging fruit"-Henry Rollins.
The evil that occurred by the hand of Dylann Roof could have been avoided. A teacher that took interest in him, a set of friends who got him interested in games (even on the internet), a parent who filled his time with something positive... but instead he was isolated and left on the internet to find evil. A club that he felt he was welcomed in, because racism is welcoming to any young white man. And then he has a group to blame his isolation on.
Do we want to stop evil from taking over? Then we need to make sure our young people are connected with positive people, doing positive things. I'm not saying it comes easy, but ignoring them doesn't work.