As an individual user (non-system admin), I want to know who else can see my card. If I share my card with someone, and then that person shares the card, I want to know that. I'd like a system alert. Also, is I specifically don't give a user access to a Project, but just to 1 card, but then that user tags that same card to another project altogether, it's defeated the point of limiting access to just the card. The user can share that card out with others I never intended to see that information.
It would be great if there were more access control options.