When you include Tags or Groups in a profile, all public tags or groups are listed for the user to select/check, however, it would be very helpful to have the option to select which tags are exposed within the profile.
If we could select the tags in much the same way we do when we're doing an advanced search, that would be the ideal way to manage these.
I'm certain there are several other relevant use cases, but ours is specifically to control which mailing lists the user is subscribed to. We want to create a profile that allows our members to select which mailing lists they are subscribed to. We have groups, for example, our trained leaders, to which we don't want users to self-subscribe, so only want administrators to add those user to those groups.