Comment by Spivak

Your phrasing could be a lot better but I think your main point holds some truth. Just like the conspiracy equation that models the difficulty of keeping a secret in terms of the number of people involved the same principal applies to online communities that have a significant number of hateful members but try to fly under the radar. It gets harder and harder for the community to moderate their members that /unjerk and then it snowballs once the seal is broken.