Why Sina Weibo blocked the account called 'zuoyeben '?

Surely because he bypass one of the non-written, unknown rules of Sina censorship :)

More seriously, he published a “self-criticism letter “ containing implicit  reference to Tian An Men events, so it account on Weibo was closed (even with more than 2 millions followers)

Source : http://chinadigitaltimes.net/chi …

This text was originally published in quora.