Mailing list etiquette

I know, having run a few mailing lists in my time, that list membership varies substantially: some people sign up the day the list is opened while others drop in and out so fast they barely leave a ripple. Apparently, some folks need a little time in a corner with a cluebat, because they've completely lost the sense of how things are properly done:

Would those of you who are on AOL and who decide that you don't want to receive list postings any longer please unsubscribe instead of reporting postings as spam to AOL? I have to spend time dealing with the fallout, and you jeopardise the ability of other AOL users to receive their mail (and not just list mail; anything else that goes through that server).

That's the administrator of one of the busiest lists I subscribe to: probably at least an order of magnitude larger than any list I've ever run. It describes a lovely sense of both entitlement and petty revenge on the part of the no-longer-desiring-to-be-members. They can't be bothered just unsubscribing, so they flag the no-longer-wanted incoming email as spam and let the big guns of the ISP take care of it for them. To call that inconsiderate is a big understatement.