Cracks down on potential infringement. http://www.bit-tech.net/news/gaming/2014/08/07/twitch-archives-copyright/1
I hear its automated copyright infringement detection system done such a good job it even silenced archived copies of Twitch's own programs.
Sounds exactly like what happened to Youtube a while back when Google started to scan videos for copyrighted music. I don't have a twitch account so I can't confirm or deny that it's similar but it sounds that way. I wonder if this is going to start to screw with people who leave the in-game music enabled or not.
I hardly view archived content on twitch anyway so it doesn't bother me much, as long as they don't scan live streams (with a short delay) and mute that then that's fine by me. I have been a victim of youtubes scanning, despite sending in numerous documents and proof that I was licenced to use the music, it still got flagged.
+1 with DriftCarl.. If they start Muting streams, then it'll fall. Quickly. For the old YouTuber crowd who now stream on Twitch, most have music on in the background etc or from others in their houses.. They can't be expected to suddenly play in silence and make everyone else in the house stop playing music just in case it's heard! (Especially if they cant have in-game music.)