Re:Facebook adds 5 divs, 9 spans and 30 CSS classes to every...
by efreak on Saturday February 09, 2019 @02:26AM
(#19121193)
IIRC you can directly download a blob from the blob internals page; I think you can also see them somewhere in the developer console, and I've got a bookmarklet that allows feeding a blob URI into it for download.
While many players, despite deeply nested html, still point directly to where the content is hosted (ex, a file on openload.co), an increasing number take your mentioned approach and load the content as a blob so folks won't bypass their ads.