Is this an appropriate way for a 13-year-old to dress?!?

I see young girls, 12 and 13 years old who dress like tarts. Those thigh high shorts are disgusting in general, but on a kid is just terrible! I really do think they are trying to grow up too quickly with such provocative clothing, but the parents are to blame for that - where the heck do kids that age get clothes like that otherwise?