Snooping, Citing, and Control+C: Internet Norms

This post on Scalzi's Whatever reminds me of something I've always wondered about with respect to the internet: why people try to limit outside access to things posted on publicly accessible pages. The forum Scalzi linked to doesn't permit "outside posting." Since he doesn't link to the forum, I can't read their rules, but I assume this means they want to ban traditional fair use like quoting for the purposes of critique. This sounds ridiculous to me, just as companies that huff and puff about people linking to their sites without permission seem ridiculous. Don't these people get the internet? It's all about linking and reading and quoting and critiquing and mashups and fisking and who knows what.

This reminds me of one of the feminist message boards I used to read. Some threads (even some entire sections) were supposed to be women-only. That's fine, and if you've got a good sense of community and devoted moderators to delete comments by men trolling where they're not wanted, perfectly doable. But certain areas and threads were not just supposed to be restricted for posting, but also for browsing. Men (and, for one section, women not "of color") were not supposed to even read those discussions. I broke this rule all the time because I was a lurker and felt no allegiance to what I viewed as stupid and unenforceable restrictions.

I learned a lot about race and about the experiences of people on the board by reading these secret posts. Certainly some of the women would not have said the things they did without the security of thinking that they were "protected" from prying eyes. And yet they were not. They could have been; they could have password protected those areas of the site and made them like friends-only Livejournals. But they trusted in the norms of their particular community, even though those norms are contrary to what I (and probably many other people) view as the very spirit of the internet.

So can any open internet community reasonably expect visitors to abide by their rules? Should we defer to those rules even when it means wrong, stupid, inaccurate, or even defamatory language is at the risk of going unrebutted? We don't let mainstream media folks and traditional literary figures get away with this sort of selective censorship of their own publicly available writings and statements. Why allow it online?