It works great until you need to add a site to the allowed sites list. There is no way to manually add a site to the list. Any site that doesn't have the little fence icon shown on the FB Login icon on the site's own page will not be allowed to be added. This is a gross oversight as there is little to no chance of being able to be compatible with the way all site display login links. Case in point, it does not work with UPS.com and I am forced to use a different browser to access UPS.

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!! ;-)))

Can't login with Facebook on certain websites and won't allow me to manually whitelist said websites either.

Good in defending the user from being track in some situation

good!