Bonfire is capable of storing totally unfamiliar activities
I did not know this! Does this mean that Bonfire stores the full RDF of the activities it receives? I don't know any other large project that does this. Anywhere I can read more about the implementation?
One problem I thought of with this, is that your server can end up storing and forwarding data that is hidden to moderators. I can think of a few mitigations, but I'm interested what @Bonfire is doing.
Yeah the server stores the JSON for any objects that aren't implemented by any extension enabled on the instance, but also display those in feeds and threads, with a best effort to generate a preview based on looking for common metadata properties, so they can still be flagged and displayed in moderation queues.