I think it is possible to expose yourself to contrasting opinions, if this is what you want to do. But another interesting thing is the way slightly different formats either allow for it or preclude it. Blogs, and especially networks of blogs, often end-up in groupthink, at least with respect to the terms of debate. I suspect there is something to the politics of linking about this. But this point is also true of social cliques generally. Messages boards seem more open, but of course they are not totally open either. And anyway - as we know from /b/ - maybe total openness is not really desirable.
i suppose there has to be a medium range, though. not the chaos and inevitable fall into the profane, and shocking to shock, that /b/ became (at least parts of it). nor the self-referential, linking to each other circle of groupthink that you reference in regards to networks of blogs, or forums borne of networks of blogs.
i think some message boards find that middle ground, or try to, but invariably clumps of people join together and as you mention, social cliques are formed, and they either are the people who are constantly talking each other up (good point,
xxx! otm,
xxx! self-reference becoming group-reference, so to speak). or, there are the pairs or small groups who just enjoy sparring with each other; knowingly baiting each other, calling each other out, playing games of semantics (because message boards are a
game of words). even in the spats and flame wars that go on, that is a type of social clique behavior.
i don't mean to say that i've never been a part of an online group/community/message board/forum that i did not learn from, or meet people i would not have met elsewhere (
or talked to, at least). but, for the most part, if i silently watch, sitting on my hands, i notice the pairings, the groupings, the intentional sparring, and the social construct that is truly hard to miss.
and honestly, even on the 4chan group i witnessed, despite being
anon, i still noticed the group mentality going on.