In response to the 20th anniversary today of the crackdown on democracy demonstrators in Tiananmen Square, government censors have blocked access  to many international Web sites and caused temporary closures of domestic online forums and blogs. The scientific community, too, is feeling the heat.
ScienceNet.cn , an online forum for the Chinese scientific community that hosts thousands of blogs , closed its comments function from midnight to 8 a.m. on 4 June (Beijing time) “due to server technical maintenance,” the site announced (cache ). ScienceNet.cn, by no means seditious, carries discussions about academic misconduct, relationships between advisers and grad students, how to publish papers in international journals, and other academic matters. ScienceNet.cn took the precautionary measure, says an editor, because they don’t have staff to monitor the site at night, which is required by censors.
More drastic measures have been taken at www.newsmth.net , which began in 1995 as a student-run electronic bulletin board at Tsinghua University and moved most content off the campus network after the university blocked off-campus traffic to the site in 2005. The site now has only a home page (cache ) with the announcement saying access to its web and blog content is down from midnight 4 June to midnight 5 June (Beijing time) for “system maintenance.”