Cheng Jianping, a Chinese social activist, has been arrested and sentenced to one year in a labor camp for retweeting a message from her fiance, Hua Chunhui. The 46-year-old woman insists that the message was a joke. According to the BBC: She had repeated a Twitter comment urging nationalist protesters to smash Japan's pavilion at the Shanghai Expo, adding the words "Charge, angry youth".Last month, Japan and China diplomatic relations were strained over disputed islands in the East China Sea.