China blocked the search terms “big yellow duck” and “June 4” and even “today” on social media network Weibo on June 4th, the 24th anniversary of Tiananmen Square massacre, after a meme of the iconic “Tank Man” photo popped up and was shared widely.
The picture (as above) shows a defiant citizen staring down a line of big yellow toy ducks instead of tanks, and is a tongue-in-cheek reference to the famous 1989 pro-democracy image of protest.

The iconic “Tank Man” photo of a man blocking a line of tanks on Chang’an Avenue near Tiananmen Square in Beijing on June 5th, 1989.
Authorities are always quick to clamp down on any online acitivity and discussion related to the violent 1989 crackdown in Tianenman Square. Searching banned terms on Weibo return a message which reads “According to relevant laws, statutes and policies,” the results of the search “cannot be shown.”
However, Chinese netizens turned to clever imagery to evade censorship, embedding their comments on the 24th anniversary in meme-like pictures, which are harder for automatic censors to detect. Along with the duck image, a LEGO reenactment of the Tank Man image was posted on the Chinese website, Netease, before being taken down:
An Angry Birds version also circulated briefly on Weibo before it was removed, and a numeric reference to the anniversary, the number “64″ lasted as one of the top searches on Weibo before it too was blacklisted. Along with online dissent, protestors in Hong King organised a campaign on Twitter to urge people to wear black tee-shirts as a sign of protest.
(Source)