Reading about #secushare, a distributed obfuscated social network framework build on top of #PSYC and #GNUnet. Lots of interesting technology in that stack, like pub/sub multicast without having to rely on clouds. They're quite critical of the federated approach for anything where one might want privacy, or just not want one's social graph easily mined

http://secushare.org/ or http://secushare.cheettyiapsyciew.onion/