Twitch probably shouldn't have done that.
When you're a streamer, it's probably not wise to promote another streamer. While that's a normal rule when it comes to competition in the overcrowded game streaming space, it seems like Twitch isn't giving people the choice. Advertisements for Ninja's New Year's Eve event showed up on streams of other people like "Dr DisRespect." It's safe to assume that this didn't go over well, and the popular personality and other streamers called out Twitch for promoting a competitor on their channels.
Full story from the WindowsCentral blog...