I am very familiar with a large American MNC operating in China. In my exposure and work with them, we had at least 3 high-level “overseas Chinese” employees who were secretly consulting with, or selling advice and experience (secrets?) to local Chinese enterprises, who were competing with my employer.
For their part, this American company stupidly pursued “management localization” in all its Asian operations, for both short-term cost savings, and giving the company a “Chinese face.” Thus they faced this problem, again and again, over and over.
I’ve worked in large aerospace companies. I am stunned when I see foreign nationals working there with the company’s most secret of secrets. The companies scratch their heads wondering how their trade secrets made it to China, Russia, and India.