A woman works online in a Beijing office. (FREDERIC J. BROWN/AFP/Getty Images) A woman works online in a Beijing office. (FREDERIC J. BROWN/AFP/Getty Images)

It's one of the great ironies of present-day China that the world's largest and arguably most successful socialist state, a "people's republic" ruled by a supremely powerful Communist Party, can at times be quite hostile to socialism and communism. That's not exactly a secret, but a bit of Web censorship on China's most popular Web portal today has provided an almost too-perfect symbol of that contradiction.

Today is International Worker's Day, marked around the world every year by labor and socialist movements. That should ostensibly be a cause of tremendous celebration in officially communist China. But not on China's most popular Web site, Baidu.

Baidu, which is ranked as the fifth most popular Web site in the world, above even Wikipedia, contains Google-like search features, discussion boards and a Wikipedia-style encyclopedia. One of its many popular functions is a tool that allows users to start discussion threads around popular topics on the Web encyclopedia.

Today, in China, you can read Baidu's encyclopedia entries for International Worker's Day, Karl Marx, labor unions and strikes. But the entry for International Worker's Day makes no mention of the recurring holiday, only its 1899 genesis. And, more tellingly, Baidu today blocks users from starting discussions on any of these topics.

According to Fei Chang Dao, a blog that monitors free speech issues in China, Baidu users are blocked from entering or starting chat threats tied to any of these topics. Also blocked are "proletariat," "workers" and even "socialism." Yes, in the world's largest communist state, socialism is too hot to discuss.

Despite the seeming contradiction here, this is actually quite consistent with Chinese Web censorship practices. Anything that might inspire public gatherings or be used to encourage them is a top target for Web censorship in China. Since the 1989 student protests that culminated with a military massacre of civilians near Tiananmen Square in Beijing, the Chinese government has shown extreme caution edging into paranoia about any politically tinged public gatherings.

Now, protests still happen anyway, and can happen quite frequently in more rural or remote areas. But the point is that Chinese officials very much do not want to see people marching in the streets waving flags and chanting slogans, as they often do in other countries during International Worker's Day. If enforcing that desire means imposing some extremely ironic and potentially embarrassing Web censorship, then, likely from their view, so be it.