The Chinese government has a major problem with the truth. This stems from the fact that China has a lot of problems (economic, political, cultural, ecological), and does not want a lot of irate citizens second-guessing how Communist Party officials cope (which can range from either ignoring issues, or trying to implement an unpopular solution). State controlled media rarely even mentions these problems. Instead, there are lots of stories about problems in other countries. As far as the Chinese mass media is concerned, China is the best of all possible worlds. But the people know better, and the government tries to cope with this.
For example, the government controlled media makes a big deal about how bad, bad, bad corruption is in China. Lots of publicity is given to the prosecution of corrupt officials. But the truth of the matter is that most of these thieves get away with it. The government fears that the spread of this news via the Internet and cell phones will result in widespread unrest that the provincial governments will not be able to handle. So far, there are no signs of a widespread organization of pissed off people. But movements like that have arisen many times in the past, and most government officials not only know this aspect of Chinese history, but really fear a reoccurrence of it. For many Chinese officials, it's not a matter of if there will be a rebellion against corruption, but when.
Meanwhile, forbidden information gets through. While the government censors the Internet, there are lots of leaks. Many tech-savvy Chinese know how to get around the "Great Firewall of China." These Chinese spread the truth via cell phones, often using code words (that constantly change as censors catch on and block those terms) to describe what is really going on. Every year, thousands of Chinese are arrested, and many punished, for "information crimes." But there are over 400 million Chinese Internet users, and twice as many cell phone users. The truth is out there, and most Chinese can, if they care to (and many don't) find it. It's not a matter of if, but when.