On May 28, 2009, the readers of artist and activist Ai Weiwei's blog — hosted on Sina, a popular Chinese internet portal — logged onto blog.sina.com.cn/aiweiwei to find the message "This blog has already been closed. If you have queries, please dial 95105670." That message is still there, although the number has changed. Dialing it takes you to an unfolding origami of recorded options that would frustrate the most hardy call center veteran. When human contact is finally made, an explanation as to why the blog was shut down is not forthcoming. Nor, for those who've been following Ai's career, is it necessary.