In the lead up to the 24th anniversary of the 1989 Tiananmen Square massacre in China on June 4, censors in China were ever vigilant to try and prevent efforts to commemorate the massacre, officially spun as a counter-revolutionary riot, on the internet. As well as blocking obvious search terms, censors also blocked keywords such as "today," "remember," "that day," "special day," and combinations of the numbers "4" and "6". As always, Chinese internet users have gone to creative lengths to get around the censorship, with one Weibo user posting a picture parodying the famous "Tank Man" picture from the massacre using yellow rubber ducks. But censors have reportedly blocked access to that too.

Along with big yellow ducks, here are some of the other bizarre things that the Chinese government has censored, from penis-shaped buildings to empty chairs:

1. Big Yellow Rubber Ducks

Chinese censors have reportedly blocked searches for the term "big yellow ducks" on the popular microblogging site Sina Weibo in the lead-up to the Tiananmen anniversary. The meme parodies the iconic image of a lone man facing up to a line of tanks during the protests. Other parodies, involving cows and Lego, have also been appearing on the internet.

2. Leaders Doing 'Gangnam Style'

In 2012 a fake photo of Chinese leaders, including new President Xi Jinping, previous President Hu Jintao, and Prime Minister Web Jiabao, doing the dance from Psy's "Gangnam Style" was posted on the internet on the first day of the Party Congress. Censors quickly pulled the image.

3. Penis Shaped Building

Earlier this year, the new building of the People’s Daily newspaper, the official paper of the Chinese Communist Party, was subject to widespread ridicule on the internet for resembling a penis. So censors decided to block searches on Weibo for keywords such as "People’s Daily" and "building."

One creative Weibo user photoshopped the image of the building together with an image of the headquarters of Central China Television to create this delight:

Image credit: Weibo

4. An Empty Chair

After a picture of the empty chair reserved for Chinese Nobel Peace Prize winner Liu Xiaobo at an awards ceremony in Oslo was posted online, Chinese censors quickly removed it. The writer, professor, and human-rights activist was unable to attend the ceremony because he is currently serving an 11-year jail sentence.

5. Time Travel

In 2011, Chinese censors issued new guidelines which all but banned TV shows that feature time travel. Although it did not ban them outright, the guidelines, reportedly in response to the popularity of shows, such as Palace, in which people travel back to ancient times, said that such shows "lack positive thoughts and meaning" and some of them "casually make up myths, have monstrous and weird plots, use absurd tactics, and even promote feudalism, superstition, fatalism and reincarnation."

6. The Stock Market

After the Shanghai Composite Index fell by 64.89 points on June 4, 2012, censors blocked the keywords "Shanghai stock market," "Shangai stock," and "stock market" on microblogging sites in China. Why? Because it was the anniversary of the Tiananmen Square massacre which occurred on June 4, 1989: 6/4/89. And the government does not want people searching for terms that will bring up anything related to the massacre.