@hoergen Hmmm, maybe I'm all off here, but ... this somehow feels like a problem that has been solved in the past, and be that as simple as in e-mail: Sending messages to a wide load of recipients with all of them in Cc (because I want to discuss issues with all of them), anyone who responds to any of these messages will send this response to all of the original recipients, and that is intentionally and expected to be this way. If someone modifies the set of recipients - fine, of course everyone's able and allowed to do that, that's a conscious decision, but it's not, like "no matter what - your response will only be seen by those people in that recipient list that have you in their address book"... . Maybe this analogy is a bit difficult, but at least that's a kind of behaviour that, for an addressing as generic as "Following", would somehow be not all too much off.