[jckt]

I think the Internet as it was originally designed would have had the opposite effect. I mostly browse the "old" Internet -- i.e. static pages and the like. And all I really see is a diversity of opinion. It's honestly difficult to find someone I completely agree on any given day.

But the rise in "recommendation engines" (Facebook, Tumblr, etc) and even "news aggregators" (yes, the irony) may indeed impart the provincial-ising effect you mentioned. As people are automatically fed information that they have been measured to prefer, they end up grossly overestimating how widely-held their views really are.