This year there is nothing they can do.
Enforce a proper zero political or sexual dress code.
Prohibit any non-guardians (sex partners) from atending the event. Federal land so 1996 DOMA applies. (IOW as a matter of law no heather has two mommies.)
Anyone causes problems they are out. Anyone makes offensive sexual related comments they are out.
NEXT year move to invitation only.
It's never been by invitation only. It's one of the last real "for the people" events we have here in Washington.