Anna Cinzia Squicciarini Alexei Czeskis Abhilasha Bhargav-Spantzel Privacy policies compliance across digital identity management systems. 72-81 2008 SPRINGL http://doi.acm.org/10.1145/1503402.1503416 conf/gis/2008springl db/conf/gis/springl2008.html#SquicciariniCB08