In China it has become the not-so-secret community where ideas and information get shared out of the reach of the censors and over jealous authorities. And - taking its lead from the global microblog Twitter - China's Weibo is providing a generation of internet users with access to news and comment about what exactly is going on in every corner of the country.
Weibo is the microblogging service set up in August 2009 by Sina.com following the mainland Chinese government's decision to block Twitter and other social networking sites (such as YouTube and Facebook) in June of last year. The fear was that these sites would be used to stage protests or gather people together to mark the 20th anniversary of the Tiananmen crackdown.
But the move has instead created a stream of similar local services that have in the past six months doubled their audience so that they now boast 103.1 million users combined.
And while the likes of internet providers Tencent, Sohu and Netease have their own microblog services, Weibo is proving by far the most popular, holding down 40 per cent of the market, according to internet trend watchers iResearch. And analysts are now predicting there will 253 million Chinese microblogs by 2013.
The problem for the authorities then is that as well as Chinese citizens, the Chinese media are using the microblogs to find out what is going on in a country that likes to keep a close check on exactly what information is released.
To keep the authorities happy, Sina.com, for example, says it has a team of "thousands'' monitoring content to keep controversies to a minimum. "Content monitoring is a headache,'' one Sina.com editor told Hong Kong's South China Morning Post.
If something is deemed touchy, the blogger will be contacted and asked to voluntarily delete the posts. And if that doesn't work, Sina.com removes them.
With China's internet community now standing at some 420 million people, due to simple weight of numbers those stories are still getting out - a recent spate of Jiangxi province villagers protesting against forced eviction is one example that not only got blanket coverage in China, it eventually reached a global audience.
And just as Twitter has its "tweets'' Weibo has its own name for its postings. "Wei" in Putonghua means micro and "bo'' means blog but when put together "weibo'' sounds very similar to the word used for "scarf." And so it has come to pass that to post on Weibo - in 140 characters or less, as on Twitter - is to "knit a scarf."
How they line up ....
Twitter - 175 million registered users; 95 million tweets per day.
Weibo - 50 million accounts; 25 million daily posts.