This paper assesses the efficiency of various forms of protection of personal data adopted since the seventies (government regulation, market regulation, self-regulation) in the prevailing context of massive use of digital social networks (DSN). The authors show that new forms of self-exhibition, combined with multiple information leaks, challenge the social norm of privacy and make any kind of structurally corrective regulation ineffective. Any solution aimed at controlling the flow of personal data is confronted with exorbitant transaction costs and would seriously hinder the innovation processes surrounding the diffusion of RSN. The article concludes by examining possible ways out of this structural deficiency of regulation.