Well, the plot thickens!
Either TPG, AIOE and Eternal September all do their own filtering for spam
(not very likely, as there _is_ spam frequently appearing in other
groups), or Google (the most prominent injection point for spam) is
issuing cancels which the aforementioned servers are honouring but
GigaNews (from which iiNet apparently collects its news, based on your
comment and the supplied headers) isn't.
Maybe iiNet's too engrossed in their takeover efforts to establish their
own proper news server? :-P
Anyone using a news server other than the ones already mentioned here,
care to comment about whether you see such spam or not?
--
Bob Milutinovic
Cognicom