快闪党 (flash mob / kuài shǎn dǎng) is a “public gathering of complete strangers, organized via the Internet or mobile phone, who perform a pointless act and then disperse again.” Though the concept has existed in the past, the modern version was popularized by former Harper’s editor Bill Wasik, who organized a series of gatherings throughout New York City in 2003. They were mostly social experiments or a sort of performance art, and soon spread across the globe. This is in contrast to a “smart mob,” which is more directed and typically has a goal, the dîner en blanc phenomenon for instance, where people dress in all white and gather at specified locations for a secret dinner.
Why it is blocked: Even though most flash mobs do nothing more harmful than show off a few Michael Jackson pelvic thrusts, Chinese authorities still fear the idea of large numbers of people organizing in public spaces, perhaps viewing it as training for future political gatherings (the distinction between a flash mob and a protest hinges on intention, but execution-wise, they are similar: see for instance the 散步 / “take a walk” demonstrations). Flash mobs, though often harmless and playful, have caused disorder and even violence in other countries, a situation Chinese authorities no doubt are keen to avert. (Flash mob is currently blocked on Weibo.)
As a Chinese college student,I usually gather my friends to use flash mobs publicize our campus activities.If flash mobs are blocked in college,a lot of fun will disappear.