YouTube starts out with an advertisement and after 3 seconds, you can click skip to watch the video. If you don't get that message due to the action of an AdBlocker, yahoo will harass the user by repeatedly interrupting the p[playback of the video. There are hidden AdBlockes such as Free Avast which includes an AdBlocker automatically applied towards YouTube. So we have two issues here. The known AdBlockers and the hidden AdBlockers. Also YouTube is behaving badly towards Firefox users even though we didn't do anything wrong. They just don't like Firefox users.