From China Digital Space
kōng yǐzi 空椅子
Writer and dissident Liu Xiaobo, who was sentenced to an 11-year prison sentence for "inciting subversion of state power" on December 25, 2009, was awarded the 2010 Nobel Peace Prize. Unable to attend the award ceremony in Oslo, the laureate was represented by his empty seat. Shortly thereafter, the term "empty chair" became a sensitive word in Chinese cyberspace.
Some bloggers who used the term "empty chair" in their posts had their accounts blocked, while others who participated in a campaign to post images of empty chairs saw their posts censored. Some accounts were deleted simply for posting the image.