The author of one of the China weblogs I put in my top ten a while ago has been detained by the PSB. He was last known to be filming a documentary on underground churches in Beijing.
Some people are expressing skepticism at the power of a weblog to free somebody like Hao Wu. But it's not about directly freeing him, it's about showing support and creating awareness, and hoping that the site leads to action by people who can make a real difference. So in a sense the focus/title of the weblog is misleading, but the intent is right.