Demetria Devonne "Demi" Lovato (born august 20, 1992) is an american singer-songwriter, musician, actress, and anti-bullying spokesperson. She is also involved in philanthropic activities through charity work and various social and environmental causes. Lovato's earliest roles included angela on barney & friends before rising to prominence as a starring cast member in the 2008 film camp rock. In 2009, received her own television sitcom, sonny with a chance, and was a starring cast member in the film princess protection program.