One could take the attitude "When in Rome..." regarding the Yahoo! controversy over information provided to the Chinese government that resulted in a Chinese dissident being put in jail. In fact, that would have to be the Left's multiculturalist view--who are we Americans to define how another country should run itself?
Or, one could take the attitude that it's an evil thing, but it's justified by Yahoo!'s presence in China, which will inevitably help that nation turn to freedom via access to better information. This position's a little weak, for many reasons, not the least of which is that I'm sure Yahoo! censors its search results and other information based on the direction of the Chinese government. So, it's probably not doing much good even in this regard.
Finally, there's the mere fact that Yahoo! really has little choice in what it does, as long as it's doing business there. Would Yahoo! have been able to refuse to hand over the information? I doubt it. I have a feeling the Chinese government would have gotten their hands on the information one way or another.
That leaves pretty much the only option that Yahoo! should refrain from doing business in China. So far, thought, it's owners (that is, is shareholders) haven't decided to do so. Maybe enough of these sorts of events will change their minds.