Addressing the Address Books' (Interdependent) Privacy Issues

Interdependent privacy (IDP), which refers to situations where individuals affect the privacy of others, is a growing concern and has been studied in various contexts. Digital address books (DABs), where users store personal information about others on online services, are a compelling yet understudied case of IDP. In this paper, we present a multi-faceted analysis of DABs. In particular, we conducted two online survey studies with N = 463 and N = 459 DAB users to understand how they interact with their DABs, perceive and manage associated privacy risks, and support data protection rights. Our studies notably reveal that (i) the privacy leakage due to DABs is substantial, (ii) users are well aware of the privacy (incl. IDP) risks of DAB data but have only moderate privacy concerns and are quite comfortable granting access to this data, and (iii) users are relatively open to respecting the rights of data subjects. We conclude with concrete design recommendations for a privacy-aware DAB ecosystem.