...make that "there"...

I assume you are referring to the advertisers?

We could try complaining to their ISP, or something... although if
they were to use a proxy they could easily overcome this... perhaps we
could try a DOS attack directly on their connections...

Actually, if we all teamed up together and wrote a long ranting
message of complaint to their providers I'm sure we could have some
kind of influence... But who are we to whine. This is a free
newsgroup, advertising is just something you have to accept in an
unmoderated group, and ignore it the best you can.

It would be great if they were all using one of the more common giants
in email service, such as hotmail or yahoo, as that way we could just
complain to them. Unfortunately they seem to be using private email
hosts, so this would be ineffective.

The common perpetrators seem to be:

watches0...@global-replica-watch.com
service0...@watchec.com
wholesale replica bags

If we can get these three off there would be a whole lot less spam in
production.  On the other hand, there are many ways to filter them
out. If you are currently using Google Groups, then you'll have to
learn to live with it, but if you are using a newsreader, most of them
come with a kill file function. So Google users can try switching to a
newsreader they find they might like.  Hope this helps.