http://cwtchim3z2gdsyb27acfc26lup5aqbegjrjsqulzrnkuoalq5h4gmcid.onion
Even in experimental group chats which do rely on a routing server, the server learns no information about which messages belong
to which group, who is a member of which group, or who messages are intended for. We believe that our tools should help people resist surveillance. Communications metadata is known to be exploited by many adversaries to undermine the security of systems; to track people;
and to conduct large scale social networking...