[TigerLikesRooster]

These people are not spies in a classical sense. They are usually ordinary Chinese who are leaned on by Chinese intelligence to cooperate. They have no years of training at a spy school. They are assigned to handlers who are spies. They will bring all kind of stuffs to their handler. Then handlers need to sift through them, find something useful and send it to their headquarter.

It is a dragnet operation. Nobody is a spy from start. So I am not sure marrying a Chinese woman/man from Mainland China is a good move if you deal with sensitive materials at work. Chinese intelligence will find you spouse and "persuade" him/her to cooperate. Of course, if you are an ordinary person, there would be no problem.

[AdmSmith]

China is taking small pieces from many (=the masses). In a way it is an extension of what Mao said:

We should go to the masses and learn from them, synthesize their experience into better, articulated principles and methods, then do propaganda among the masses, and call upon them to put these principles and methods into practice so as to solve their problems and help them achieve liberation and happiness.

“Get Organized!” (November 29, 1943), Selected Works, Vol. III, p. 158.