While presently enjoying a tremendous popularity among Internet users, Online Social Network (OSN) platforms have also recently increasingly come under fire for a number of security (and privacy) issues stemming from their usage. In an attempt to somehow formalize the study of such issues, we propose in this paper a conceptual model of the workings of a "typical" OSN platform as experienced by its users, putting a distinct emphasis on the resources published through such platforms for the pivotal role they have come to occupy, notably in regard to misuses. We then briefly discuss potential applications of that model, not only as a support to assess security properties inherent to the configuration of current OSN platforms, but also as a tool to further investigate practical attack scenarios against those (and their users).