Actually TC, I think you're coming off too soft, if anything. I would be livid!
It should be downright obvious that you can't drink on a college campus and the other stuff isn't allowed anywhere. Let's call these ruiners what they are, "Jackholes" (that's me being polite).
Comes down to the responsible players having to take on yet more responsibility by actually stepping up and saying something when they see idiots attempting to ruin it for the rest. If you see people doing crap on the course they shouldn't, regardless of which course it is, "Say something". Be as polite as you can, start with explaining that you just want to keep the courses open and maintain a good relationship between disc golfers and those who own the land we're using for FREE... then go from there.
Sorry to hear about it TC. I hope karma visits these idiots with lost discs, lots of bogeys and perhaps a concussion from their own drive double ricocheting off two trees.
2013 STLDGC Tag #107
2013 SCCDGC Tag #78