Retrieval of personal public data on social networks: The risks for privacy

In this chapter, the authors analyze the risks for privacy coming from the distribution of user data over several social networks. Specifically, they focus on risks concerning the possibility to aggregate user data discovered on different sources into a single more complete profile, which makes possible to infer other data, likely set as private by the user. In order to show how it is possible to human users as well as to software agents crawling social networks, identifying users, linking their profiles and aggregating their data, the authors describe the prototype of a search engine they developed. The authors also present a simulation analysis to show the retrievability of user data by using a combination of people search engines and they provide statistics on the user perception on this issue.