People posting the pictures should wear all black and put up the pictures. After putting up the pics they should spray the pics lightly with some kind of color that will not easily come off and add an irritant. (Hopefully they will touch parts of their body). :)
Pepper spray. It’s an oil and sticks to skin.
CC
Color? Well, maybe for starters. I’m thinking itching powder. Caustics? Oilly stuff. Lemme look around the shop. I’m pretty sure there’s a dozen ways here to break the poster ripping habbit.