What I like most about the web is how the anarchy of it all encourages niche groups that never would have formed otherwise. The most common example, I think, is the gay teen in Idaho who might have killed himself if not for some online gay teen community.
On the other end of the spectrum, perhaps, is Conservative Veggie: "for the veggie who's right." Discussion topics include "What Do You Think Of Alito's Investment in Slaughterhouses?" "Vitamin D 3," "Churches are Ignoring the Plight of Animals," and simply "Guns." I just love how the people have almost nothing in common beyond being vegetarian and voting Republican.