[Projoy] I see almost no spam at all on Usenet. I read mainly rec.arts.sf.* and a few others. Where do you get the idea that it's mostly spam? (Er, I probably won't see a reply to this for a couple of weeks -- off to Glasgow at the crack of dawn tomorrow.)
[Raak] Well, as you won't see this I can make any claim I like. :) I don't know, but I assume the admin of some newsgroups have anti-spam measures in place, or there are anti-spam measures at the ISP news server level. No idea, really. I also have frequented a rec.arts newsgroup or two (and I believe the drwho one still goes on strong). I used to read a group or two on the alt. hierarchy, but would not attempt it now. They were swamped in spam years ago.
all the usenet groups I ever use (a few music ones and tomb raider, all under alt.) are filled with crap. I looked in on the MC one this morning and that was full of rubbish. a shame really. I'll try other groups though.
I regularly look at, and contribute to uk.sci.weather. There are rather a lot of gadget nerds and people of the spotty-herbert tendency who seem to use weather as an excuse for computer exercises but there are also professional meteorologists who contribute, necessarily under a pseudonym. There is very little outright junk.