I like how SoundCloud and Vimeo have their various tabs synchronized so as soon as you start playing something in one tab, the other tabs pause. What's more interesting is that this only works on SoundCloud when two instances of the website are open, but for Vimeo this happens even between a Vimeo website tab (with the video playing) and a Vimeo video embedded on say The Verge (http://www.theverge.com/2014/12/22/7433775/watch-the-styles-of-your-favorite-directors-recreated-with-stock). However when the Vimeo video is embedded on Facebook (when I had shared it) it doesn't work.
I was wondering if one of the techniques mentioned on Javascript: sharing data between tabs is used here and if yes, why doesn't it work when the Vimeo video is embedded on Facebook and I have another tab playing Vimeo video.