I just added this addon to Firefox and tried it out on FB and nada, blocked zero adds. Refreshed page, closed and reopened FF and the same result. Nothing. It will block elements readily but adds were still profuse.

Apart from an occasional nudge they show, to rate the plugin (once every month or so I guess, not more) - the plugin has prevented so many ads from showing.

This add-on has its own ads pop up to block the browser screen as here:
https://ibb.co/N2PBm0R

If the computer is in unmanned operation mode next time, will it cover the display of important screens?

it brock only one site and still the best

Amazing! Kudos4u all =D

Sometimes it's a little slow, but I have literally no ads so it's great!

good so far.