Does anyone know how lenient big tv shows such as Americas Got Talent or American Idol are towards marijuana use prior to contestants performances?

How lenient do you think big shows are towards marijuana use prior to each episode. The only reason i ask is because ive been involved in the music and entertainment business for years and its no secret that marijuana use is very common, and most commonly used just prior to performances. I cant imagine that these shows would be too open to the idea of it, but it wouldn't surprise me if nothing happened to the contestants if they were to be found smoking before performances Has anyone been on the show or known anyone on the show that could speak of experiences?