Towelie is the best example. He constantly streams random games under World of Warcraft. A lot of other partners do this too (and WoW is one of the most popular games to do it under). You're allowing two things to happen: Making a game look more popular than it actually is, and making it unfair for streamers who are actually streaming the game.
Please moderate this.
Ask Twitch.tv: Why do you allow partners to stream under the wrong game? | Heykuki News