You click a link to a news site, to read an article that seems interesting.
On the page that loads there is the article, but also, somewhere on the right, often near the bottom, there is a small video player. Inexplicably, it was not blocked by your ad-blocker.
It is auto-playing a news video that is not connected to the article. Sound is often on.
You:
@rysiek but autoplay with sound is blocked in any browser by default 
@termonoid I am going to be there are JS ways around this