Leyla Bilge Thorsten Strufe Davide Balzarotti Engin Kirda All your contacts are belong to us: automated identity theft attacks on social networks. 551-560 2009 WWW http://doi.acm.org/10.1145/1526709.1526784 conf/www/2009 db/conf/www/www2009.html#BilgeSBK09