Lol! You don’t even have to look at what these people would do to the grounds. They always trash their venues.
I say give the crowd a break. They all flew in and out on unicorns, magic carpets, or by using pixie dust. Not many trash cans available through those modes of transportation. The great thing that they didn’t use one drop of oil or bit of coal power in their trips.
Greta Thunberg sings her UN speech;
https://www.youtube.com/watch?v=CLxpgRqxtEA