Charlotte - 
“Privacy” is a back burner issue for now. I work with some “sensitive” groups and I remind everyone that nothing posted anywhere on the internet should be considered “private”. If any member of your group receives posts via individual messages or digests, even if you delete that post it lives in posterity. There are things an individual can do to mask their identity (different email, not using identifiers in posts) but you can not assure members of total anonymity. It might be more appropriate to move this query to the GMF https://groups.io/g/GroupManagersForum/topics

Patti