Efforts are being made to prevent autoplay videos. Nextbigfuture is talking to the ad networks to prevent autoplays.
Preventing autoplay videos with browser settings.
Chrome
Click the menu icon on the upper-right corner and select Settings.
Then scroll down to the bottom of the page and click the Show advanced settings link.
Scroll down further until you find the Privacy section. Click the Content settings button.
In the resulting Content Settings dialog box, scroll down to the Plug-ins section. Select Click to play, then click the Done button in the lower-right corner.
Add Chrome Extension
Starting in Chrome 64, autoplay will be allowed when either the media won’t play sound, or the user has indicated an interest in the media. This will allow autoplay to occur when users want media to play, and respect users’ wishes when they don’t. These changes will also unify desktop and mobile web behavior, making web media development more predictable across platforms and browsers.
Not all users have the same preferences for autoplay media, so Chrome 63 will add a new user option to completely disable audio for individual sites. This site muting option will persist between browsing sessions, allowing users to customize when and where audio will play.

Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.
I may be wrong but I do not believe that these instructions would block the autoplay of a javascript baed player like JWplayer which is commonly used on sites liike CNN to play disruptive popup videos. Automatically playing video and audio is a disturbing trend where content providers are shoving media down their users’ throats; In my opinion all efforts should be made by the browser developers to provide effective tools for mitigating this distractions.
I particularly like the way that the “Preventing autoplay videos with browser settings.” link page has an irritating autostart video on a totally unrelated topic.
I recently made a ‘lifestyle choice’ of sorts. I disabled Javascript, Cookies, Flash and Autoplaying Videos/Audio by default on all websites.
No I haven’t gone completely insane, I added a few extensions that let me create a whitelist exception for a website with a single click of a button in the toolbar. If anything isn’t working, I enable what’s needed and leave it at that.
I’ve noticed a definite improvement in my browsing experience, websites seem to be much more responsive and faster loading. The web has really become a cluttered mess in the last few years, it may be time we start disabling things more aggressively to clean it up.