If they do something like this, it wont be because of piracy, it will be because it will harm rentals and the second hand market. The latter is something they care about far more than piracy and I'd say it loses them far more money than any amount of piracy.
But once again it doesn't lose them any money... If I couldn't trade games, I'd buy less second hand games, and the guys upstream would buy less because they wouldn't have my cash from buying their second hand games. In any case, the loss would be completely unquantifiable anyway.
And, unlike piracy, selling used goods isn't in breach of any laws whatsoever.