yep, there is no case to cry foul here. StackOverflow clearly provided license to copy. Maybe they did no expect something like this China copy to happen. But that's the beauty of a permissive license. I think its great that StackOverflow chose to use Creative Commons.
Crying foul here would be no different than Debian being offended by Ubuntu.
Moral of the story: if you don't want people to use and build on your work, don't license it permissively.