Are they good people if they ignore what is in front of their face? If they actually don't see what is going on that's a little different. However, those that have known and ignored should be dealt with just as those that have done the deeds are being dealt with now. One step-at-a-time. Gather up the main people then come back through with the broom and dust pan to collect anyone that was missed. That would be the right thing to do.