http://safeon6m5sm4pyxjenu5d4yyt3d4v7twonxrxcwkp5xdsodux2nunoyd.onion/blogs-forums-social-media/facebook-dark-web
Prior to the release of an official .onion domain, accessing Facebook through Tor would sometimes lead to error messages and inability to access the website. ProPublica explicitly referenced the existence of Facebook’s .onion site when they started their own onion service.