Surprised to see alt.arts.poetry.comments on this list. Yes it remains active, but the regular posters there[1] are for the most part the remnants who triggered the Great Poet Flight to various online (moderated) forum venues 20 years ago.

Some of those troll fights were fun. Some even involved poetry.

Also: obligatory link to the Usenet Poetry Groups "Rogues Gallery" that I created prior to the Great Poet Flight: http://www.rikweb.co.uk/photos/rogues-gallery.html

[1] - https://groups.google.com/g/alt.arts.poetry.comments