Does what it says on the tin, with no unexpected side effects.
(to those who complain about not being able to use their facebook login on other websites: this is expected behavior and explicitly mentioned in the description!)

Addon works as expected, but I don't understand why it has to be a separate addon when you could simply add a clickbox to every container to work like this. I would like to isolate more websites than FB.

REALLY GREAT TOOL!!! CONGRATS!! ;-)))