Should Internet discussion lists and newsgroups be moderated?

The other day, someone asked me:

Do you believe newsgroups should be moderated? If so, what content should be excluded?

I answered him as follows and would like to share my answer with you.

The major problem of unmoderated newsgroups is the boring postings, not the controversial ones. I mean, the stupid flame wars, "one liners", unsubscription requests, ad nauseum. The controversial ones (no matter from what side of the public opinion) are INTERESTING and worthy of reading. I believe that there should be BOTH moderated AND unmoderated groups. The moderated groups are for busy people who want to keep track of the subject but don't have time for the trash postings. The unmoderated groups are for leisure time and to preserve the freedom of expression of people.

NOTE: the above was written before spam was a serious problem.