If
@anihilnation said was true then this was after free parking and to see a movie, so the groups probably didn't even step in the parks. You get two or more antagonist groups around each other then fights happen. If Universal wants to solve the issue they need to go beyond hiring more security and installing more cameras. I was responding to your complaints about theme parks adopting curfews chaperone policies and how it would cut off future theme park fans.
Two things happen with companies that have security-related issues - they either get them under control or they go out of business. Universal will likely implement more security.