to delete archives and silence streams containing music, a service where gamers can broadcast and share live video of their adventures online, will detect and mute streams containing copyrighted audio–which is, of course, many games. Previous footage hosted at the service will be deleted, beginning in three weeks.

We respect the rights of copyright owners, and are voluntarily undertaking this effort to help protect both our broadcasters and copyright owners. …We've partnered with Audible Magic, which works closely with the recorded music industry, to scan past and future VODs for music owned or controlled by clients of Audible Magic. This includes in-game and ambient music. When music in the Audible Magic database is detected ("Flagged Content"), the affected portion of the VOD will be muted and volume controls for that VOD will be turned off. Additionally, past broadcasts and highlights with Flagged Content are exportable but will remain muted.

The Audible Magic technology will scan for third party music in 30 minute blocks — if Audible Magic does not detect its clients' music, that portion of the VOD will not be muted. If third party audio is detected anywhere in the 30-minute scanned block, the entire 30 minutes will be muted. ..

As for existing past broadcasts, beginning three weeks from today, we will begin removing them from Twitch servers. If you would like to keep your past broadcasts, we encourage you to begin exporting or making highlights of your best moments so that they're saved for posterity.

The background here is that Google reportedly bought the service for ~$1bn a few weeks ago. Copyright enforcement on the music industry's behalf, well beyond the provisions of copyright law, is business as usual for YouTube. But this is the craziest content policing scheme yet: in order to prevent people from hearing music buried under relentless sound effects and low-quality voice chat, they're going to broadcast silent video game streams. What fun.