Petition: Smite only for jungles!

Just had a troll in ranked who was queued for mid but insisted on playing jungle. Our team didn't realize until it was too late to switch champs. Since we now had two junglers and nobody mid, the game was ruined. I reported him, but who knows if he will receive some action.

So here is my proposal: Make smite unavailable for anyone who is not queued for jungle. There is no reason anybody should ever be able to pick smite outside the jungle role, and this will ensure that people can't troll like in my game.

What do you guys think?

Edit: I see people are concerned about this limiting the potential to trade roles. How about adding a "trade role" option during champ selection?