I'm currently using nightly and, while videos with audio are muted by media.autoplay.ask-permission, and further they are paused if you also set allow-muted to false, the problem is that they still load. On a metered [or slow] connection, this is a big problem. Viewing a news article on ABC [for example] pre-loads the entire video in the background. To make matters worse; Even after the entire video has been cached, a steady stream of 200KB/s is still continually streamed from the CDN. Example link: https://abcnews.go.com/US/noreaster-season-east-coast/story?id=58738494 If you monitor bandwidth with Firefox's network monitor, or a 3rd party tool [like jnettop for Linux], you'll see that the page continues to load video data. Not only would I expect it to not load any if playback is disabled, but it certainly shouldn't continue to load data, perpetually, after the entire video has been buffered.