.. note:: Account membership is permanent. Once added, users cannot be
removed from their account.
+.. warning:: Ownership of the user's notification topics will not be
+ transferred to the account. Notifications will continue to work, but
+ the topics will no longer be visible to SNS Topic APIs. Topics and
+ their associated bucket notifications should be removed before migration
+ and recreated within the account.
+
Because account users have no permissions by default, some identity policy must
be added to restore the user's original permissions.