It's coded into the web page and not easy to block. There are add ons like https://addons.mozilla.org/en-US/firefox/addon/greasemonkey/ that let you do amazing things but here's the rub. You get to figure out how to block, alter or change what the offending site is doing.
HOWEVER did you try your browser's "Reader View"? I did and the videos vanished.
For Firefox I used this link and add on: https://addons.mozilla.org/en-US/firefox/addon/activate-reader-view/
You click to go to Salon, say, for an article, or Reuters, for the news. As their page opens, there is a video that begins to show site content or an ad. Often you can click it to stop, or 'X' it in the corner to have it go away, but sometimes it plays on.
The big problem is that when you scroll down to find the particular title or text you were actually looking for-- the Video frame scrolls right down as you go. Sort of 'follows' the reader down the page.
I need to get rid of this in W10, but mainly I need to know what this is called. (I've tried searches like 'disable frame-in-frame' or moving-screen or other terms and no luck).
If I know what it's called, I can search to find how to disable it. (Also should mention: this isn't a standard 'pop-up'. It has sanctioned site material-- news clips or whatever the site is about-- as well as including ads.) I'm using IE11 which doesn't take secondary adblock apps.
What is the 'moving vid screen' thing called, please?
Thanks very much.