How do you do that? Once she joins the team, you have no way of knowing if something Ann created or modified belongs to the team or to her. This is the classic problem with "taint checking." Once you mix data across boundaries you have to assume it's tainted. I agree it's a crappy situation, but I can't see what Dropbox should change, other than make it very clear how this feature works to future customers. As a one-time thing, they could maybe get a PR win by helping this guy recover his data (if possible). However, that's not scalable, or a precedent they'd want to continue forward.