Starting in September with Firefox 41 you can set media.autoplay.enabled to False in about:config and stop them from playing automatically. https://bugzilla.mo

Starting in September with Firefox 41 you can set media.autoplay.enabled to False in about:config and stop them from playing automatically. https://bugzilla.mozilla.org/show_bug.cgi?id=659285 https://bugzilla.mozilla.org/show_bug.cgi?id=659285