Yet another technology implemented by Mozilla in Firefox with nary a thought to its potential harm.
In Firefox to disable, do:
§Enter “about:config” in the address bar and press enter
§Press the button “I’ll be careful, I promise!”
§Type in “media.peerconnection.enabled” in the search bar
§Right-click the entry choose “Toggle”, the column “Value” should now be “false”
This vulnerability is also present in Chrome but I don’t and won’t use that privacy-thieving piece of shit so I have no idea how to disable it there.