A US teenager convicted of using Facebook to blackmail dozens of male classmates into sex was sentenced to 15 years in prison.

AN 18-year-old male student is accused of posing as a girl on Facebook, tricking at least 31 male classmates into sending him naked photos of themselves and then blackmailing some for sex acts.

An American student was accused today of posing as a girl on a internet social site to trick male classmates into sending him nude photos which he then used to blackmail them.