Actually after reading @cel's last comment, I think yes the thing in the original post could be very easily achived - just make a PR to ssb-viewer to add robots.txt by default. Opt in per thread is too complicated, not being indexed by goog does seem like a reasonable user expectation. For messages/threads that are shared outside of ssb (like, in a blogpost) would still be searchable by finding that blogpost and clicking through. This seems like an okay-in-the-short-term solution? @tiago?