Global content revocation on the internet

Common wisdom holds that once personal content such as photographs have been shared on the Internet, they will stay there forever. This paper explores how we could allow users to reclaim some degree of their privacy by "revoking" previously shared photographs, hindering (but not eliminating) any subsequent viewing or sharing by others. Our goal is not to build a system that can withstand determined efforts to subvert it, but rather to give well-intentioned users the ability to respect the privacy wishes of others. Achieving this goal at scale will eventually require the participation of large content aggregators, and they are unlikely (putting it mildly) to find our proposal compelling. We therefore propose an approach we call technology ecosystem transformation (TET) that begins with a transitional and more easily deployable (but not fully scalable) design that does not require the participation of large incumbents but is designed to change user and societal expectations enough so that these companies would find it in their interest to adopt the approach we propose here. The intellectual challenge in this TET approach is finding transitional designs that (i) have parties willing to deploy it and (ii) once deployed, would change the incentives for the incumbents so that they would be willing to adopt the proposal.