Here is an interesting view of the Internet in China from a student's point of view.
"Since you already know the truth that so many web sites are now unable to visit from mainland of China. Today I'm going to tell the reason of it and introduce the great wall in the invisible cyber world. It all begins with the Great Firewall, which is the biggest digital boundary in the world. It's not a sort of software but a system that isolates China from the global Internet.
"The purpose of the system is to filter those web pages containing sensitive topics, which are considered to be harmful and are likely to shake the stability of the country, including politics, freedom of speech, Tibet independence improvement and so on. According to the survey of Harvard, over 18,000 web sites are blocked by the GFW, including Facebook, Twitter, BBC, even Google are blocked every now and then. For those large web companies, if they want to develop in the mainland, their servers must be set in Beijing, so that the authorities are able to censor the data rigorously. Google can't accept that and pull out from China and set its server in Hong Kong.
"Since you already know the purpose, next, I'm going to illustrate to you how the GFW works. Normally when we click a hyperlink, we are actually sending a request to the servers which will immediately reply with web page files we clicked. We know that.
"But with the GFW lying between your PC and the server, the authority will censor the content and decide to block it or not. If the page does include some sensitive topics, we are not able to see the pages. That's why you often see the browser indicate '404 NOT FOUND.' We have our special term for that: River Crab, which is the phonogram for harmonization or censorship. That basically how it works.
"In conclusion, just like it's said in 1984, "Big Brother is watching you" and you do everything under the censorship of the government. They have everything in their hands. The Internet belongs to all mankind, and it needs to be free and the wall is bound to collapse."