A simple solution, slow but effective and will require some janitorial cleanup work: LOCK THE DOORS TO THE PUBLIC RESTROOMS.
They’ll just go on the floor and their cohorts will smear it on the walls.
They’re screaming “Recall Walker”. That just shows how ill informed they are. Walker could not be recalled for a year, at the soonest. To call them idiots, would be an insult to idiots everywhere!