There's a giant issue with that, though: in bigger channels, the chat goes by way too fast to moderate. You see someone say something awful and by the time you can even click on someone to ban them you have 20 other people saying equally horrible stuff. It's like trying to hold back a tidal wave of shit with a bucket.
That and for whatever reason, fighting game streams tend to have something dumb like 10x the chat activity of other games on a per-capita basis. If a FG stream ever hit LoL numbers (without doing something like sub only or slow mode), Twitch's chat servers would melt.
