OSN: When multiple autonomous users disclose another individual's information

Online Social Networks (OSNs) are becoming more important in the web 2.0 paradigm. Although most implementations of OSN are not distributed applications, users conforming an OSN work autonomously posting their information in the OSN and interacting among them. Users are responsible of the information they post in their profile and, in the vast majority of social networks, they can limit the disclosure degree of such data regarding the members of the social network. However, a part from data they provide, other related data can be obtained from users: the relations between them. By appropriately crawling the web, it is possible to obtain information from a single user without accessing to his profile. In this paper, we present an attack to users' privacy using a specific crawling algorithm that takes advantage of the network properties of OSNs.