Most of the calls here are scammers claiming that your relative(s) have been arrested in China, then offering to help get them released. There's plenty of first generation immigrants who (a) have money and (b) worry about the parents or spouses they left behind in China.

Harassing people into giving out their personal details by claiming they're from immigration, at least according to some articles on the subject.

I got one of these while applying for a Chinese bussines visa. Scared me a bit because the only person I knew that speaks mandrin only really understood enough to tell me it was was "Chinese immigration" wanting money and info. Ended up forwording it to our immigration lawyer who told me what was a scam.

Calling from immigration... in Chinese?! This is supposed to be US immigration?

One must look under the lamppost. This is a sales funnel, and the undocumented Chinese immigrants who fall out because they can't understand English will outnumber those who don't believe immigration can speak Mandarin.