Rebecca McKinnon has a highly interesting posting on her blog about recent research she has done at the University of Hongkong. (Unfortunately her blog cannot be easily accessed in mainland China. Even the RSS Feed in Google Reader is blocked.)
Following up on a conversation McKinnon had last year with BOB 2008 award winning Beijing lawyer Liu Xiaoyuan, she did some empirical study on how much chinese blog service providers (BSP) interfere with their hosted blogs on sensitive topics. It turns out that what Liu had observed with his own blogs is true: There is a high degree of variation. Of the 108 entries with sensitive content that McKinnon and her teams consistently posted on 15 different blogging platforms the most rigorous BSP deleted 60, the most lenient only 1!