On July 16, 2012, famous Chinese blogger, venture capitalist and social media researcher Isaac Mao  wrote on Twitter  [zh] that he would be shorting  $SINA every day from June 17, in reaction to SINA Weibo's (a Chinese microblogging platform) deletion of his user account.
As he has used StockTwits  special tag “$+ stock symbol” in his tweet, his message has been delivered to investors from all around the world via the investment communication platform. On the next day, July 17, SINA's NASDAQ listed price dropped by 8%.
Isaac Mao: Short $SINA's share
Below is Isaac's Twitter message  [zh] from July 16:
自6月17日新浪微博刪除我賬戶以來，以每天平均10條微博，10美元/條的低價索賠，並發分析新浪審查自毀的信件給全球基金經理建議“削” $SINA 股票
In his letter, Isaac further explains  why he has decided to short SINA's share:
I'm shorting $SINA everyday since 6/7 along its downhill, then spending the earnings to buy other stocks.
Why? Unlike your thinking on Sina's climbing up with it's “growing” number of Weibo users, instead, it's going downturn in any ways:
1. Sina is boasting the biggest user based in China on microblogging, however, the data is questionable. In my guess, 1/4 of its accounts are zombie,1/4 frozen,1/4 spammer,1/4 guided voices
2. Sina keeps deleting high quality but political-sensitive accounts in hundred of thousands rate a month, but keep them in census to advertisers. Sina reportedly make fraud by itself by faking million-follower accounts to mislead advertisers.
3. Sina deployed a series of regulations on real name verification and community peer watch rules, all failed now since never has a consistent principle. Real users are losing interesting posting relevant information there
4.QQ weibo is catching up, outpacing Sina as the top microblogging service, though Sina still keeps some celebrities there. Most of those public voices have dual account on both QQ Weibo and Sina Weibo.
5. Apart from user's counting complains, Sina itself has to face the risks from authority as well. In a leadership transition year,Sina may not be able to keep Weibo service live, most probably. There will be several big inflexions upcoming in China, keep eyes open.
The power of #socialnomics
This is not the first time Isaac Mao has campaigned against global corporates  [zh]:
Back in 2006, there was a campaign to show netizens’ support for bloggers such as @mranti at MSN Space [whose blogs were removed  [zh] as Microsoft was eager to enter the China market] and the service was crippled in 2009. An open letter was issued to Google  warning it against self-censorship practice in 2007, Google decided to leave the China market in 2010. Now that Sina thinks it could do whatever it likes back home, it is digging a deeper grave.
The connection between social media and economics is getting tighter, in a field called #socialnomics. It is about the impact of social force on economic index. The image of a brand would affect its value. SINA thinks it is OK to delete their users’ account. This is a signal for its demise.
As Isaac Mao's action has resulted in such a visible consequence, his account at StockTwits was suspended on July 18 at 00:35 Beijing time.
Chinese netizens have been pressuring SINA against its censorship practice, such as the mandatory real name registration system, since 2011. A few months ago, a number of Chinese netizens also issued an open letter to the investors of Sina , which also urged investors to cut their shareholding in SINA:
The Chinese government’s policy on Weibo has a significant effect on the prospects of Sina. Holding the shares of Sina Corp entails tremendous uncertainty. On 20 September 2011, the share price of Sina dropped by 15.17% to US$92.76, the greatest daily drop since December 2008. Sina’s market capitalization has shrinked by US$1 billion to US$6 billion. Market commentators attribute this drop to concerns over regulatory risks.
On 17 October 2011, Beijing Daily published an anonymous op-ed titled “Lack of credibility will mean the end of Weibo”, which calls for a real-name registration system for Weibo.6 The article criticizes the serious shortcomings which come with the rapid growth of Weibo. If left unchecked, these problems will threaten the society. It urges the government to purify the Internet through more comprehensive and targeted measures so that new media will be responsible for ensuring integrity. It suggests that the government should fully implement a real-name registration system for Weibo and an accountability system for online media. Guangdong’s Southern Metropolitan Daily thinks that “a strict real-name system may drive away users.”
In a recent interview with CCTV’s program Economic Half-hour, Sina CEO Charles Chao commented that Weibo will be the future driving force of Sina.8 China’s regulatory policy towards Weibo will undoubtedly have a significant impact on the prospect of Sina. As social conflicts are becoming more acute, the government’s control on the society will tighten, and the space for free speech will shrink. In this context, Internet censorship will undoubtedly be strengthened, and the possibility of the Chinese government shutting down the microblogging services will always be with us.
Perpetrators and their collaborators should be punished. We hereby urge investors to reduce their shareholding in Sina based on both moral and rational judgments, thereby indirectly applying pressure to Sina and its microblogging service to get them onto censorship practices based on clear and transparent principles.