In 1984 Beta Theta Pi was the first GLO to require a chapter to have a 2.5 cum GPA in order to not be suspended (we have annual conventions). I think it was early in the 90's when they also required a 2.5 from all members. You have to have 2.5 to initiate, and actives that don't get 2.5 they go on probation-required study hours, and loss of voting privilages in chapter, and sometimes social probation as well. If they have two consecutive semesters under 2.5 then they go up for member review which could lead to having to turn in their badge.
I don't think at Nebraska any of the sororities has under a 3.0, and I doubt a Frat has a GPA under 2.7
It definetly bothers me that some groups would have such a low GPA. It really demonstrates how few chapters or GLO's are working everyday to uphold the ideals of their founders.