Re: constitutional issues, to me this just falls in the category of spying, and would be handled, coordinated, or bankrolled by the CIA. The CIA has already done much worse things than hack into Chinese government servers. If the CIA does not have the infrastructure for secret, untraceable hacking of foreign servers, then I think we're going to be ill-prepared for the future.

Whoever wrote the brilliant Stuxnet worm http://en.wikipedia.org/wiki/Stuxnet (probably Israel) has a great cyberwarfare program.

American hackers generally hate oppressive governments, so I'm surprised there aren't more freelance, independent, pro-bono efforts of the sort.