Benjamin Greschbach Gunnar Kreitz Sonja Buchegger The devil is in the metadata - New privacy challenges in Decentralised Online Social Networks. 333-339 2012 PerCom Workshops http://dx.doi.org/10.1109/PerComW.2012.6197506 conf/percom/2012w db/conf/percom/percomw2012.html#GreschbachKB12