Quoting Felipe Sateler <fsateler@debian.org>:
Is there a way to mark network connections as "expensive", and thus u-a does nothing if only connected via that? It would be very annoying to have packages automatically downloaded when tethering my phone connection.
Good point! Even Wifi might be cheap or expensive, depending on the situation. At home or in the office it might be an almost unlimited resource, but if one is in a hotel or elsewhere one might have traffic limits based on MAC or room number. An upgrade might prevent users from being able to read their email afterwards.