I didn't know these groups existed on FB until recently when they got notice in the upper echelons of WP blogs and newsletters. All the complaints in blog posts and comments about FB's suitability are right, from their perspective, but I'm impressed with how well these groups work. It's like trying to drink from a firehose if you try to "keep up" with them, but the sheer volume of their posts and comments seems to be a kind of strength -- individual personalities can't dominate them. The big ones are a low friction, low barrier way for anyone to join in a reasonably healthy, helpful, practical and social dialogue that's not clogged up by either the 1337s or the n00bs. This is the living image of the "Army" that is WordPress, as Brian Krogsgard put it recently.