Sigma Nu started at VMI. One of the better frats IMO.
Started at VMI, but as an alum, I can tell you all frats were disbanded for being disruptive to the corps.
Maybe things have changed and no doubt they are different at different colleges/universities.
Back in the day, mid-70s, middle of the night, bunch of Sigma Nu busted down the apartment door of my girlfriend (wife now) and her three roommates, ransacked the place and then discovered they were at the wrong apartment and on the way out, said “That's okay, we're Sigma Nu”. . .and wandered off into the night.
Sigma Nu refused to repair the door and the girls had to go to the Greek Council (I think that was what is was called back then) to force Sigma Nu to pay for damages.
Sigma Nu was, of all frats, the foulest and most out of control of them all. . .and not in a funny Animal House kind of way. Every Friday night they would basically take over a local bar and start fights with non-Sigma Nu students and chase them away. Not a weekend went by without the police arresting several Sigma Nu for assault.
So, maybe they were a different breed where you were, but at Southwest Texas State University in the mid-70s, they were a criminal enterprise. Cheers