Miley Cyrus has hit back at the people who left comments on her social networking site calling her fat.
It all started after the Hannah Montana star posted a comment on her Twitter page joking about her wobbly thighs.
Miley was talking about a picture taken of her in a bikini on the beach while she was on holiday.
As soon as comments started appearing on the website, Miley posted one of her own - cyber-bullying can seriously scar people, making them hurt themselves.
Miley said: "Talk all you want. I have my flaws. I'm a normal girl. There are things about my body I would change, but stop with calling me fat."
Although Miley Cyrus is a big star, she is no stranger to bullying. In her book, Miles To Go she talks about what she went through when she was younger.
Bullying is not new - but cyber bullying is growing really fast.
Cyber bullying is when you are being bullied via a mobile phone, text message, emails, phone calls, chat rooms or through social networking sites.
Experts say they reckon this type of bullying is far more upsetting than school bullying because nearly all of us can be contacted 24 hours a day by any of those mediums.