Brings to mind the response when a drug dealer tried to sell to kids outside of my school. The head master, both deputy heads, and the 7'4" caretaker escorted him well away from the school property. I heard he went and stood outside the "sister school" (by which I mean another grammar school closely associated with the one I went to) nearby instead and no one did anything about it over there
both schools have similar good reputations in terms of academic achievement.