I mentioned the trash to one of the leaders I passed on the trail...he apologized and said he'd talk to them about it when he got to camp. I said, "They're just kids...they'll learn. They just need somebody to teach them." Hopefully they'll remember it for next time.
But like I said - at least they were out in the woods, and most of them appeared to be having fun. Once they're bitten by the bug, they'll realize the importance of the rules so they can enjoy it with their kids in the future.