Facebook announced today that the social network will now be directly available to users as a Tor hidden service. The Tor Project is an Internet-traffic anonymization service that relays user traffic through a number of proxy servers all around the world in order to cloak true IP addresses and identities. Tor users can connect with similarly anonymized Web-servers located in the onion top level domain. Facebook s cooperation with Tor carries a broader message about legitimate use of the so-called Dark Web
Source: https://threatpost.com/facebook-creates-onion-site-now-accessible-via-tor-network/109121/