That's a very fair point. A problem with anonymous identities though also comes where you have features at the edge that 'do things' based on the identity. Often you will just want an anonymised unique identity for each discrete user, but not necessarily their real identity.
Food for thought... Would there be a way to achieve this with federations that maintains anonymity? - List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html
