What sort of recourse would handle this in your eyes? I'm not familiar with Twitch's policies 4 years ago, but what you described would fall under their rules about harassment nowadays. Twitch seems to either temporarily or permanently ban users who violate their policies, but honestly it takes repeated mistakes, except for the most heinous of cases, to be permanently banned. Users have been held responsible for the actions of their chats, or harassing other streamers by hosting them or 'raiding'. I think a lot of this would be / could be prevented with the newer establishment, but I'm not sure what sort of response you were looking for from Twitch.