The Great Firewall of China, well publicized in the internet community, is a prime example of political/security/fear censorship. The firewall denies users within China to access politically sensitive information around the world. If you want to get a taste of the censorship, download and install the Firefox plug-in China Channel and you can find out firsthand the nature of the firewall. You can try some of the known blocked sites listed here.

You can download a copy of Firefox from Mozilla.

China Channel is a simple proxy that let your browser behind a China IP address. When turned on, you will be accessing the internet as if you were in China. The response time would be rather slow as you are running through a proxy server from the other side of the earth.

Get a feel on what it is like. There is no guarantee that you would enjoy the same level of freedom you have now. An aggressive administration can change it with little notice. Even if the supreme court catches up with the action, it will be many years later.