Recently there were a bunch of announced arrests of Chinese American scientists and the indictments of Chinese nationals for spying or/and economic espionage. For Chinese who are naïve about American laws who aspire to be Americans this is a sobering warning that should be taken seriously. As Snowden revealed NSA spies on everyone, but especially foreign national that considers as enemy. Any innocent meetings with former colleagues and mentors and exchange of scientific ideas may be construed as spying or economic espionage. As China develops her own science and technology while U.S. lacks resources due to financial difficulty, many sees more opportunity in joining or starting their own company in China. They are somewhat naïve in believing the freedom of expression and exchange, but U.S. is very strict in interpreting the laws and embargo cutting edge science and technology to China. If you worked for U.S. government or any companies with contracts with government or even performed research resulting in patents that belonging to the company, then you may be in violation of obscure laws if you try to strike out on your own. Downloading files to your own computer as Wen Ho Lee discovered can result in spy charge. Recent case of Goldman Sack against Sergei Aleynikov, even if the 97 months jail term were reversed can be debilitating.
I was naïve also after 1979, when U.S. and China established normal relations. I was working in Alaska in a Dew Line communication site which was frontline against possible Russian nuclear attack. I wrote a letter to the new Chinese Embassy in Chinese expressing my pleasure on the new relation, and inquire about visa procedures to visit China. After about a month of no response I was surprised to learn from my boss in Anchorage, that an FBI agent will be chartering a plane to interview me. The agent spend a couple of hours asking my background and nothing affecting my secret clearance came to pass, but it was an unnerving experience, and I never did hear back from the Chinese Embassy.