Spam avoidance

[Douglas Alan]

I've noticed that there is little to no spam in comp.lang.python and
am wondering how this is accomplished.  Is there a moderator who
actively cancels spam?  If so, that wouldn't seem to prevent spam from
making it through to the mailing list version of the newsgroup.  Is
there an exceptionally good spam filter in place?  If so, I haven't
previously seen one that works so well.  Have spammers just given up
on Usenet, figuring that there are more exciting places to spam than
the Big 8 dinosaur?

The reason that I ask is that I help to run another newsgroup
(rec.music.gaffa) and we avoid spam by requiring that every
participant who wants to post has to register on a Mailman.  But I
think that this approach has the seriously detrimental effect of
discouraging new participants, so I've been wondering about
alternative approaches.

|>oug