Having read through the homepage of that site, I can see some absolutely fundamental errors in the logic which have very possibly allowed these people to become so exploited:

The focus of Falun Dafa practice is the mind, with the cultivation of one’s mind and thoughts, or “Xinxing,” being singled out as the key to increasing Gong energy. The height of a person’s Gong is directly proportionate to that of his Xinxing. The concept of “Xinxing” encompasses the transformation of virtue (a white form of matter) and karma (a black form of matter). It also includes forbearance, discernment, and abandonment—that is, forsaking ordinary human desires and attachments, and managing to endure the most trying of ordeals. Much is encompassed by the concept.

My regular readers will know that I write a great deal about emotions and will. When we become so focused into the mental and deny our desires, we invite suffering and the opposite of what we really need. It is, sadly, not surprising to me that those who deny their will and desires are finding out how terrible the results can be for them. :/