Marketing thongs for six to ten year old girls, what are the pros and the cons?

I do not know the outcome but I read a news clip online about either a manufacturer or a retail outlet that was taking heat because they wanted to market a line of thongs for girls six to ten years of age. In this “Do what feels good, so long as you are not hurting anyone” ideology, what would be the harm in girls that age wearing thongs? If you are not oppose, what are the pluses you see?