Mark: "I have rather given up on the Acorn Usenet groups and the Iyonix mailing list as they have increasingly become rather depressing places"
Haven't we been here before? Your description of the Iyonix mailing list doesn't bear any resemblance to what I generally receive from it. Maybe you missed my comment about the last time someone talked about recent incidents there, so I'll repeat myself:
"all the Iyonix list saw was a few dozen angry emails. They have now stopped (although perhaps not in the best way), and the list has gone back to its usual quietly helpful self."
"Compare this with other RISC OS-related mailing lists, which can see hundreds of off-topic posts in a similar timescale... and no end in sight despite the problem having persisted for some years now and having been addressed in a variety of ways."
As for usenet groups, yes they contain a lot of argument, but that's just their nature. To suggest that you've "rather given up" on them now, seems to imply that things have somehow become worse than in some, dare I say it, former golden age. This just isn't true, unless you believe the golden age was in about 1992 or something.
I've never unsubscribed to the Iyonix mailing list, there really never has been any reason to, it's almost always on topic and definitely always helpful - and has only seen a very few, very brief arguments. For less focused mailing lists and newsgroups, I sometimes subscribe for a while and sometimes unsubscribe for a while. But I always understand that subscribing and unsubscribing is down to how much time or patience I have for such things at that particular moment, not because a mystical golden age has somehow passed, or the level of arguing has somehow got worse.
In short, if one becomes temporarily (or permanently) not in the mood for the sort of thing that happens on usenet, one needs to unsubscribe from usenet - not assume that usenet has "become rather depressing" just because your mood has changed.
Sorry for the rant, I'll try and keep them on usenet in future