@silverpill Re Versia Unfollow: I think one of the big mistakes of AS2/AP/AV was using generic Activity names for almost everything. The only types that don't have issues is those that embed Objects in them and Add/Remove which explicitly operates on Collections only.

But things like Follow... Follow what? A user, a context URL for following threads? Interpret it however you want, have fun. The distinction between Objects and Activities isn't even necessary when you stop doing this generic approach. Not like Activities aren't "special" Objects anyway.