Chinese dissident e-mails: what did Yahoo know, and when did it know it?

Chinese pro-democracy activist Shi Tao was sentenced to 10 years in prison back in 2004 after Yahoo turned over his e-mails to the Chinese government, but the company has publicly claimed that it had no information about the case when the government first demanded the e-mails. Now, an alleged copy of the official request for that information has surfaced, and it suggests that Yahoo did have at least some knowledge of what the case was about. Whether the company should have acted differently because of that is a matter for debate.