I've spent some time in China and found Twitter, Facebook, Blogspot, BBC (just to name a few) to be entirely blocked while I was there.

While it's debatable as to whether or not these Western websites are important to average Chinese, it seems like a mischaracterization to say blocking several of the top 10 most popular websites in the world is "very limited."

Another experience which spooked me a bit (I don't know if it was purely coincidental or not): I was visiting some fairly obscure websites while I was there and they were accessible. Yet, within a few days after I first visited them, some of them were blocked. That made me wonder if there are human beings checking websites to decide whether or not they need to be "harmonized" (Chinese joke).