Hi,
I will add a feature in the next release so that you can specify roles allowed to view member list in web.config
This will be easy to implement so I will do it in the next few days, I will post here again once I've implemented it in svn and you can do your own build if you need it before next release.
This solution will have a limitation in that if you are hosting multiple sites on a single installation this setting will apply to all of them since they share a common web.config file. Later on I will implement it better so each site can have its own setting for this.
Thanks,
Joe