Also, here is the greek life link from their panhellenic counsel. It lists the ones who are part of the official process as well as giving lists of the disaffiliated and those that were kicked out.
https://fsl.umich.edu/
It also explains Rush in detail etc. I think it is helpful for a student to be fully informed, but I have heard of several UM students who rush because they met a few people they liked and just go off their word. Greek life is controversial everywhere, some huge supporters, some huge detractors. So the more information an individual can get the better.