How to Hide Firefox Camera Icon Overlay in Windows

You can also add this to UserChrome.css

#webrtcIndicator {
  display: none;
}

Source: reddit

(Settings) Hamburger Menu -> Help -> TroubleShooting -> Profile Folder -> Open Folder -> create folder chrome -> inside chrome create userChrome.css -> contents of userChrome.css:

#webrtcIndicator {
  display: none;
}

Then //about:config Then flip toolkit.legacyUserProfileCustomizations.stylesheets to true

Restart Firefox

No wonder they are losing marketshare with such user-hostile behavior

In the about:config settings, set privacy.webrtc.legacyGlobalIndicator to false.

Unfortunately, the only way to do this is to write a custom add-on it seems. I just encountered a similar issue where I had to remove the overlay for an embedded application.

You can download the add-on here.

Note: This add-on should only be used if you have valid use case for it (like in these two cases), as the developers introduced these privacy and security enhancing features for a reason.