What would be your specific proposal? Members only forum? High karma only? invite only?
I should probably mention that this has been discussed before. An invitation-only mailing list was the proposal being thrown around back then, but some fairly reasonable-sounding objections were also brought up. I’m not sure whether the signaling problems of organizing (as pedanterrific put it) secret-society stuff outweigh the signaling problems of discussing the same subjects publicly (though I suspect the former is preferable), or whether either one brings a net gain over not discussing them at all (less sure about this one), but in light of the OP I thought it was worth revisiting.
I should probably mention that this has been discussed before. An invitation-only mailing list was the proposal being thrown around back then, but some fairly reasonable-sounding objections were also brought up. I’m not sure whether the signaling problems of organizing (as pedanterrific put it) secret-society stuff outweigh the signaling problems of discussing the same subjects publicly (though I suspect the former is preferable), or whether either one brings a net gain over not discussing them at all (less sure about this one), but in light of the OP I thought it was worth revisiting.