Reporting from Beijing
"There are 400,000 words in the English language, and there are seven of them that you can't say on television…. They must be really bad."


In 1972, comedian George Carlin wrote a monologue titled, "Seven Words You Can Never Say on Television." When a version of this riff was broadcast the following year on a jazz radio station, it set off a legal battle that went all the way to the Supreme Court, which ultimately upheld the right of the Federal Communications Commission to regulate indecent material on the airwaves.

Nothing is quite so clear-cut in China, especially when it comes to the murky realm of Internet censorship. China does, of course, have its own version of the dirty words (many, many more than the seven identified by Carlin), but the list itself is confidential.

Trying to figure out what is banned and what is not has taken on new urgency in the aftermath of Google's withdrawal from China over censorship concerns and the strong stance of the Obama administration on Internet freedom.

In China, each website basically censors itself, so though there are universal taboos — anything about Tibetan independence, for example — you are never quite sure when, shall we say, one of the seven words will hit the fan. Some words can be searched in English, but not in Chinese, or vice versa. What's sensitive one day might be legit the next.

When using websites based outside China, users on the mainland are often blocked by the so-called Great Firewall of China. But unlike the wall that you can see in satellite photos of Earth, this wall is invisible, often elusive.

The Chinese government doesn't even call it censorship, the preferred term being "guidance of public opinion." Chinese Internet users often say that a website has been "harmonized," a waggish reference to Communist Party slogans about building "harmonious society."

You don't always know when you're being censored — sorry, guided. When searching a sensitive subject, you will be frustrated with a blank screen and a vague error message ("the connection to the server was reset while the page was loading" is the most common) so that you're never quite sure if you've hit the wall or if some technical glitch really did cause the problem.

Often, the user who's tried to search something blocked won't be able to get back online for several minutes – the equivalent of a time-out given a naughty child.

There are approximately 80,000 characters in Chinese, and only a few of them are banned outright. But in combination, the innocuous fa, or law, and lun, or wheel, become the banned Falun Gong movement.

Recently, the word for carrot (huluobo) was blocked on some sites because its first character resembles the family name of President Hu Jintao. Similarly, wendu, temperature, was blocked for its resemblance to Premier Wen Jiabao as was xuexi, or study, which shares a character with China's vice president, Xi Jinping, a likely heir to Hu.

In fact, the scariest thing about Chinese censorship is that there is no list of dirty words — leaving media and Web personnel always nervous about how far they can go.

"There are explicit bad words, but the system really works by instilling fear," said David Bandurski, a scholar at the China Media Project, based at the University of Hong Kong, who in 2008 was commissioned to write a satirical piece in homage to Carlin about China's dirty words. ("This word ‘democracy' is a perilous word that must be handled with great care," was part of his riff.)

"The paranoia," Bandurski said, "is more effective than blocking certain words."