A Privacy-Preserving Architecture for the Protection of Adolescents in Online Social Networks. - Markos Charalambous; Petros Papagiannis; Antonis Papasavva; Pantelitsa Leonidou; Rafael Constaninou; Lia Terzidou; Theodoros Christophides; Pantelis Nicolaou; Orfeas Theofanis; George Kalatzantonakis; Michael Sirivianos (CoRR, 2020)