How to get my daughter to stop looking up to hannah montana?

hi. i have a 6 year old who last month saw pictures of miley cyrus in her underwear, the vanity fair, her video at the teen choice awards, the music video of party in the usa, like inapropriate thing that miley's ever done. after that, she started acting very strange. she took out 3 of my black bras from my drawer and wore them under her shirt and purposely made sure the the straps and the sides of the bra were showing. when i saw her like this, i was appauled. i asked her why she was dressed this way, and she said, "miley cyrus wore a bra in her music video party in the usa nd i wanna be just like her! don't i look pretty?" i made her change out of those clothes and give me back my bras and i had a long discussion with her on why she shouldn't dress that way. but she continued to do these kinds of things. she stole my digital camera and took pictures of herself in my bras and naked. i found out about this and punished her and put a parental lock on the disney channel, but she still didn't stop. she would still sneak into my room and watch hannah montana and steal some of my lingerie. at school last week, she wore one of my short-cut nightgowns to school (i didn't know at the time because she was wearing a sweatshirt over it) and i was told by the principle that at lunchtime she took off the sweatshirt and revealed the nightgown and that she was caught kissing two boys at lunch. i just don't know what to do anymore. please help me.