That's after the fact and after landing in US. I am not sure how those who were outside the US could have known about the university's non-existence. With so much of investment after enrolling in a uni and coming to an alien county, a lot of those students really didn't have much of a choice. On top of that, they usually don't have much knowledge of the protection that US legal system could have provided them in such a case of fraudulent uni. In my opinion, those who knew 'after the fact' were entrapped.