China again

It's all over the news - China has blocked several internet services - YouTube and Twitter and several others. Not Blogger. Not that I know of. The disconnection does not bother me - I'm not there. What I want to know is, how do they do it? Do they disconnect the servers? I have no clue. I guess officials who must maintain control must first control communication between and among people, especially dangerous people. It's like dispersing a bunch of ants. It really doesn't take much. Birds of a feather flock together. Those who are in charge and those who are controlled (or manipulated.) People are like cattle - very easy to herd. Good luck.