This document discusses how our identities are shaped by being online. It argues that when we are online through networks, our identities become multiple, public, and participatory. We take on roles like the performative self, quantified self, and participatory self. Our identities are visible, traceable, and searchable to different audiences. Networks provide greater access, diversity and visibility than institutions, but also increase noise and demands on time. The document suggests that in networks, authority comes from reputation rather than roles, and the benefits include real audiences, just-in-time conversations, and new opportunities to engage and share information. However, networks cannot control or measure participation in the same ways as institutions.