Cher Lloyd against cyberbullies
6 February 2012 Last updated at 07:04 GMT
The X Factor star Cher Lloyd has been talking about when she was bullied online.
She said she didn't talk to anyone about it because she thought she could handle it on her own but said "I think that's the worst thing you could possibly do."
Cyberbullying is when children or teenagers use the web, or mobile phones or any other technology to threaten, tease or embarrass another young person.
For more information look at the links on the left, including where to get help if you are being bullied.
Cher Lloyd's interview was on Panorama on BBC One 8.30pm on Monday.