This screenshot shows that on January 9 Sina Weibo was censoring searches for "Zhou Enlai."
By January 13, Sina Weibo was no longer censoring searches for "Zhou Enlai."
These screenshots show that Baidu did not appear to be censoring searches for "Zhou Enlai" on its web search, Knowledge (知道 "Zhidao" a Q&A service) or Library (文库 "Wenku" a document sharing service).
This screenshot shows that Baidu had apparently not banned users from creating and posting to a "Zhou Enlai" PostBar (贴吧 "Tieba") forum. However, an examination of the posts shows that there had not been any new posts on that forum since 2009. The second post from the top, entitled "Why Can't I Post?" (为什不能发帖?), explained why, and is translated here.
Why Can't I Post?
Explanation Regarding "Post Screening" and Labeling Posts "Classic" on the "Zhou Enlai Forum"!
Forum Friends:
Hello! I am "Dusk's Drunk Shadow," the former (the fourth) moderator of the "Zhou Enlai Forum." Many users can't understand the reasoning behind "post screening" and labeling posts "Classic," and even mistakenly believe that these are actions by the moderators! In order to clear things up, explain away users uncertainties, the following special explanation is offered:
1. Regarding "Post Screening"
In June 2006, because an atmosphere of pestilence pervaded many Baidu PostBar forums, a large group of users would frequently file complaints with the national Internet oversight agency. Baidu therefore temporarily shut down a large number of social and political PostBar forums and carried out censorship, rectification, and cleansing. The "Zhou Enlai PostBar Forum" was also subjected to this.
By August 2006, Baidu had completed its censorship. A large number of PostBar Forums on important political figures were completely shut down and not allowed to reopen because a lack of good management led to them having a pestilential atmosphere. Because the "Zhou Enlai PostBar Forum" had been strictly managed, it managed to come through the censorship clean and tidy and was allowed to reopen.
But perhaps because Baidu considered Zhou Enlai to be a highly sensitive political figure, the automatic "post screening" system completely halted posts from appearing that were banned from the Internet or that were uncivilized. This made everything completely safe, and never again would forum users go to the national Internet oversight agency to complain. But it also meant that forum users lost the right to freely post civilized content, and I think this point is something Baidu can't do anything about.
So I would ask forum users to understand why things are the way they are here, and not believe that the "post screening" was something imposed by the "Zhou Enlai PostBar Forum." There is only one "Forum Rule!" ("Rules" http://post.baidu.com/f?kz=5119744). And especially do not believe that the "post screening" is being carried out by the moderators. The moderators are innocent! Even the moderators themselves can no longer post!
为什不能发帖?
关于《周恩来吧》“审贴”及发贴加“经典经典”的解释！Post: http://tieba.baidu.com/p/195744953
各位吧友：
你们好！我是《周恩来吧》前任吧主（第四任）“夕阳醉影”。好多吧友对《周恩来吧》“审贴”及发贴加“经典经典”的事情搞不清楚是何原因，甚至还误以为这是吧主所为！为澄清事实，解吧友之惑，特浅释如下：
一、关于“审贴”
2006年6月，因百度的很多贴吧内乌烟瘴气，大群吧友向国家网络监管部门频繁举报，故百度公司暂时关闭大量社会、政治类贴吧进行审查、整顿清理。《周恩来吧》也受到牵连。
（事件链接：http://post.baidu.com/f?kz=110099964 ）
2006年8月，百度审查完毕。大量政治风云人物类贴吧因管理不善吧内严重乌烟瘴气遂被百度彻底关闭不予开放。《周恩来吧》因管理严格规范，故吧内整洁文明遂通过审查予以重新开放。
但百度可能考虑到周恩来也是政治敏感人物，遂开启自动“审贴”系统彻底杜绝网络禁止发布的帖子和一些不文明帖子的出现。这样就可以万年无忧、永绝后患，不会再有吧友时不时的去国家网络监察部门举报了，但这样却使文明发贴的吧友们也一起失去了自由发贴的权利，这一点我想百度就顾不上了......
所以我请吧友们了解一下此间的原由，不要以为“审贴”是《周恩来吧》的吧规，《吧规》里没这一条！ （《吧规》http://post.baidu.com/f?kz=5119744 ）更不要以为“审贴”是吧主在操作！吧主是无辜的！吧主自己都发不了贴了！
