As a resident of Beijing, I found this article from the Atlantic Monthly fascinating. It explains, in relatively simple terms, just how the Great Firewall works. I myself have been put in computer timeout quite often.
When my kids are put in timeout for some egregious violation, they still keep at it, hoping they'll succeed eventually. Unlike them, when faced with a timeout, I just give up. Which is, I suppose, why the Great Firewall works. You have to really want that information to keep trying.