Of course rivals is free, but would you object to being banned for pictures of your wife you sent out a few years back? It's a good thing you weren't in a fraternity or a student at FSU back then.
Rules are great as long as they are applied equally. Apply the same policies to all students, all teams, all student orgs.
FSU should enforce no rules against students unless they are applied uniformly across all the student population. Furthermore, no rules that violate constitutional rights, such as freedom of association, should be enforced. Frankly I am surprised that the FSU admin had not faced a constitutional challenge from banning all Greek life. I hope the Greek System lawyer's up and makes FSU pay through the nose. But there may be contracts of which I am unaware.
Go die for your country at 18, but get drug tested at State U.