i think we should switch to talking about information , not data. data is like photons, they are mediators. An agent owns his information content which is his internal thoughts and intentions. Everything he makes in your online property is a trace. The traces belong to the owner of the online property. Just like how your footsteps on my home belong to me, while your foot belongs to you. Data are measurements of those traces, thus they belong to you as well. The self-ownership of the agent's information content is not compromised.