My wife went to school (chemical engineering degree) with a young foreign student. He was very curious about life in New York, and had a curiosity about exothermic reactions and the world trade center.
She always thought there was something weird about the guy so she refused to talk to him much, especially when he asked her about her father's work which happened to be in the WTC. Then someone tried to bring down the WTC with some bombs in the parking garage.
A short while later, she saw his picture on the news. He was one of the original WTC bombers.
Yea the INS and pretty much all federal goons are incompetent and seem to be doing their best to harass citizens instead of actually controlling immigration problems, but I can't complain whenever they decide to look into someone's background before they let someone into the country. Yes, in this case it's probably overkill and yes they let hundreds of thousands of undocumented illegal immigrants in through Mexico every year, but I still can't see complaining about them when they attempt to be thorough in their checks.
And BTW, China has a VERY active intelligence program, just as active as the US and Russian/Soviet programs at the height of the cold war. Anyone failing to understand that this is a direct threat to national security is a retard. IIRC, the two most recent high-profile espionage cases both involved Chinese spies. Better safe than sorry IMHO, especially since I'm one of those who's lives are most at risk to military espionage activity.