... along with collaborators technology stolen by Chinese undergrads from leading international institutions.
Some are economic spies,some are diplomatic spies and some are military spies. Many agree to do so willingly..or even enthusiastically.
But to those who are reluctant a government agent says to them “remember,Comrade,while you're in Japan/Great Britain/United States,etc if you don't get us the info we want we know exactly where every member of your family lives”.