A streamer who I've been watching who I would consider to be a good role-model for society has had a 30 day ban because they just wanted to have fun with their community and play skribbl.io.
From what I've heard these trolls were racist and I would imagine they drew some offensive words/symbols. By banning the streamer you're giving these trolls EXACTLY what they want, put yourself in someone who enjoys others suffering for a second. Imagine if there was an action you could take to annoy a streamer, live, by being racist and also getting them banned at the same time! Well thanks twitch.tv your wishes as a sadistic racist troll have come true, just go into the skribbl.io category and draw offensive symbols!!

A good way for twitch to resolve this would be to have better communications with the streamer at hand, maybe twitch support could give this new streamer advice on how to combat these trolls and work with the streamer. I do believe that there were ways that this streamer could have prevented this, however he wont learn that from Twitch. Twitch could also not hand out punishments unless there was a certain level of negligence (you also have to take into factor if this is a new streamer or an experienced streamer, learning disabilities an whatnot), by doing this you remove so much power from these racist trolls. To not would be to give them power, to support them, to support racism.. Twitch would be supporting racism, that's not a good look, twitter would not be happy to hear this.