You may have seen these placards that went up around the neighborhood in the past several days. They contain the words of Liu Xiaobo, the Chinese dissident and Nobel laureate who perished in prison. Mr. Liu died of liver cancer at the age of 61. In 2009, he was convicted of inciting subversion and sentenced to 11 years in prison for planning a petition in support of democratic change. Liu was awarded the Nobel Peace Prize in 2010. The placards you see here were posted on the edge of Seward Park, at the intersection of Essex and Canal streets.