YouTube is trying hard enough to speed up its suicidal. First they have annoying search boxes on all embedded videos. No one liked it. They ignored.
For now, they decided to mute all videos that contain copyrighted audio track.
In another words, those funny homemade videos, screencasts, or just any other original that is using a copyrighted audio track would now be muted. Laugh all you want at the dull video that won’t make a sound.
Under all these muted videos, there will be a notice that reads:
This video contains an audio track that has not been authorized by all copyright holders. The audio has been disabled. More about copyright