Are Photos On Social Networks Really Private?

Everyday, people upload thousand of private photos on Social Networks. Usually, these photos are available only to their social friends but, in some cases, users inadvertently allow third-party applications to access their data or, analogously, friends allow applications to access their friends' data. Hence, uploaded private pictures may also be accessed by third parties. In this paper, we introduce Phook (Photo-Book), which is a Web application available at www.myphook.com, aimed at searching among users' photos of online Social Network. After two months of activity, Phook was capable of collecting more than 70 Millions private pictures of Facebook users.