Firefox already has features for blocking autoplay. I use all of those. But, some websites still manage to autoplay! Is there a way to stop those devious websites? Examples include Yahoo Finance and ESPN. I already have Autoplay set to "Block Audio and Video" in the Permissions section of Settings. I have also gone into about:config and set the following: media.autoplay.allow-extension-background-pages false media.autoplay.block-event.enabled true media.autoplay.block-webaudio true media.autoplay.default 5 Is there anything else I can do? Also, does anyone know *why* firefox is allowing these videos to play?