China’s best known artist and dissident, Ai Weiwei, was detained  in Beijing as he tried to board a flight to Hong Kong on Sunday 3 April, 2011. Ai is the latest to join a long list of human rights activists, lawyers and writers who have been arrested, detained or gone missing in the country.
It is commonly held that he is somehow protected from official crackdown by his international reputation and the status of his father, a renowned poet. If Ai is not immune, it is a worrying signal  that China’s crackdown on dissent has reached a whole new level.
Chinese artist Ai Weiwei. Image by Flickr user DigiPub (CC BY-ND 2.0).
Below are selected initial reactions of Ai Weiwei’s detention on Twitter, where some of China’s most liberal minds gather. An online Twitter petition, Free Ai Weiwei , so far signed by hundreds of people, has also been set up.
Mo Zhixu, prominent writer and critic (@mozhixu ):
3:11 PM Apr 4th
I remember talking with Ai Weiwei during New Year’s Eve. I said that the authority will find it difficult to deal with people like Ai Weiwei and Ran Yunfei, who act individually and are not affiliated with any party. They are safe. Now, events in North Africa have changed everything. Someone has to act sooner, so as to prevent the emergence of another Liu Xiaobo. However, can you say everything is alright just by eliminating the likes of Liu Xiaobo?
Chang Ping, outspoken journalist and commentator, formerly with the Southern Media Group (@chang_ping ):
11:17 PM Apr 4th
While making a speech to the media faculty of the Chinese University of Hong Kong this afternoon, I mentioned that the journalist of The New Yorker described that China’s media is entering an ice age following the detention of Ai Weiwei. This makes me think of the crackdown on the print media in 1995, which was followed by an age of explosive growth.
Liu Xiaoyun, Beijing-based human rights lawyer (@liu_xiaoyuan ):
12:14 AM Apr 5th
Ai Weiwei is being detained, his workshop being searched. Whether Ai is right or wrong, this is a big news and an important topic. I cannot imagine that the Chinese media is uniformly silent. This is such as tragedy!
Feng Zhenghu, Shanghai-based human rights activist (@fzhenghu ):
11:21 PM Apr 4th
Call for the release of Ai Weiwei, Wentao and other missing persons in China. As Lung Ying-tai said, if you think that other people’s misfortune is none of your business, then one day when misfortune descends upon you, no one will care. Protecting other people from unlawful acts is also to protect yourself.
Shi Feike, journalist and activist (@shifeike ):
8:08 PM Apr 3rd
The situation is clear. Like what I said to my friends, earlier arrests and detentions, like those targeting Guo Daxa, Liu Xiaoyun, Li Tiantian and Wentao, were just clearing surrounding obstacles. The ultimate target is Ai Weiwei. The party and government seem to be well versed with tactics and foresight.
@shifeike : 我理解，艾神的资源、个性、名气以及别具一格的刀法，使得他成为公民维权运动中的钉子户。当局此次，不过是一次针对钉子户的定点清除式强拆而已。
4:05 PM Apr 4th
My understanding is that Ai’s resources, character, reputation and unique style have made him a ‘nail’ in the rights defense movement. The authority is making a targeted action this time in order to remove this nail.
Ai Xiaoming, feminist literary scholar, documentary filmmaker and human rights activist (@xiaocao07 ):
8:21 PM Apr 3rd
Ai Weiwei is progressive. But he also mocked the ‘Jasmine Revolution’ in China, withdrew his signature of Charter 08, and even attacked Liu Xiaobo and Cui Weiping. That he can maintain his reputation is because he has done a lot of good deeds. Shouting out for children and aggrieved persons, and insisting on the freedom of expression. The present crackdown on Ai Weiwei is not targeted at the ‘Jasmine Revolution’; it is targeted at all people who aspire to justice and truth.
@xiaocao07 : 今天推特上看不到艾未未，今天，你就可以成为艾未未。如果你喜欢他，你就像他那样去生活，像他那样去爱亲人，爱朋友，爱孩子，爱小猫小狗，爱那些受苦的人并且为他们说话。无数个你成为了艾未未，中国就真正达到了幸福高指数。
12:11 PM Apr 4th
Today we cannot see Ai Weiwei on Twitter. But today you can become Ai Weiwei. If you love him, live like him. Like Ai Weiwei, love your relatives, friends, children, cats and dogs, and speak for aggrieved people. When innumerable people become Ai Weiwei, China will become a truly blessed state.
Peng Xiaoyun, opinion page editor of Guangzhou-based Time Weekly Magazine (@Pengxiaoyun ):
8:46 PM Apr 3rd
He cannot be counted as a political dissent. What he has done is just recording the names of lost children day after day. What he cares about is just a citizen’s quest for truth. What he has shown is just how an artist can participate in society. What he has called for is just the rich imagination and possibility of the individual. If even these cannot be tolerated, then it is the dead end. It is apparent that policy makers are determined to become ‘information refugees’.
@Pengxiaoyun : 至于为什么对艾动手，我想决策机制是“防卫过当”了，也属于信息不对称导致的恐惧，恐惧不独人民才有，合法性问题未能妥善解决的统治者更怕。他们对于艾在网络上一呼百应的状况感到恐惧，但我不得不说，这种网络的弱联系距离社会运动的强联系还差得老远，现在就抓人劳民伤财，维稳经费又冲天价了。
3:47 PM Apr 4th
On why the authority has decided to take action on Ai Weiwei, I think it is that the defense mechanism of the ruling party has over-reacted. This is due to fear caused by information asymmetry. Fear is not unique to the people. Rulers whose legitimacy problems are not resolved are also fearful. They are fearful about Ai’s tremendous followings on the Internet. But I must also add that such weak associations on the Internet are still very far away from those needed for a social movement. However, even with such weak associations, the authority is already arresting so many people. The stability preservation budgets must be reaching new heights.
@Pengxiaoyun : 老艾展示了一个艺术家如何介入社会，他颠覆了中国传统的知识分子形象，少了那股明哲保身的中庸小聪明和酸文人气，他有国际视野，他幽默可爱，他深谙公民运动的边界，他并不是政治革命家，不过现在当局努力在培养一位政治对手。
8:07 PM Apr 4th
Ai has shown how an artist can participate in social affairs. He has overthrown the traditional image of China’s intellectuals – self-preserving, moderate, and pedantic. He has international visions, he is humorous and lovely, and he is well versed with the boundaries of civil movement. He is not a politician, but the authority is helping to nurture a political opponent for itself.
Wang Dan, student leader of the 1989 Tiananmen Square democracy movement (@wangdan1989 ):
9:57 PM Apr 3rd
If Ai Weiwei is really being arrested, and a wave of protest does not emerge from the civil society, this will embolden the authority to arrest people at random in future. If we do not support Ai today, the one being arrested tomorrow will be ourselves.
@wangdan1989 : 讓當局停止抓人的唯一辦法，就是太多的人站出來，讓他們無法繼續抓下去。
10:01 PM Apr 3rd
The only way to stop the authority from arresting more people is to let too many people stand out to the extent that the authority cannot continue to arrest.
@wangdan1989 : 從劉賢斌到冉云飛，從冉云飛到艾未未，當局最近一連串的動作不是偶然和松散的。這顯然是經過最高當局討論批準的一個決策。這個決策是誰做出來的？胡錦濤？周永康？溫家寶？中共一定要有一個人為這次的鎮壓負責。我們要找出這個人來，聲討他，讓他成為歷史上邪惡人物的代名詞。
10:24 PM Apr 3rd
From Liu Xianbin to Ran Yunfei, from Ran Yunfei to Ai Weiwei, the actions of the authority are not made at random. This is clearly a decision from the highest levels of the authority. Who makes this decision? Hu Jintao? Zhou Yongkang? Wen Jiabao? The Chinese Communist Party must hold the person responsible for this crackdown to account. We need to find out this person, denounce him, and make his name the equivalence of evil in history.
Luo Shihong, Taiwan media academic and public intellectual (@telshl ):
8:48 PM Apr 3rd
I was optimistic about China’s progressive development and the cross-strait relations. Ai Weiwei’s detention has shaken my confidence. With such actions in the mainland, how can Taiwanese not be afraid? Does such a strong nation need to treat a mere artist in this way? After this incident, people who don’t understand performance arts will start to appreciate them.
@telshl : 艾未未不討所有人喜歡，但艾未未代表一種時代精神，一種做公民的精神，這種精神讓中國的空氣變得自由了些，使得人們可以放開恐懼去呼吸，不致窒息。#aiww
9:51 PM Apr 3rd
Not everyone likes Ai Weiwei. But Ai represents the spirit of the age, the spirit of being a citizen. This spirit makes China’s atmosphere become more liberal. People no longer suffocate; they can start to breathe without fear.