Rock fans should thank Ronnie James Dio, a famous heavy metal singer, for popularizing the “devil horns” that have become the real symbol of rocking all over the world. This sign represents power and a reference to metal music. Frontman for Rainbow and Black Sabbath assured he had borrowed a now-famous gesture from his granny who used it to ward off evil.
Ronnie James Dio
Drew Barrymore and Rob Halford
Sharon Osbourne (center) with her children Kelly Osbourne and Jack Osbourne, pose with Jack Black and Kyle Gass
Rihanna
Hayley Williams
Kid Rock
Miley Cyrus
Kate Walsh
Nick Carter (Backstreet Boys)
Winona Ryder
Justin Bieber
Jada Pinkett Smith
Sebastian Bach
Avril Lavigne
Jamie Foxx
Katherine Heigl
Bret Michaels
Mos Def
Fergie
Jennifer Love Hewitt
Audrina Patridge
Bam Margera
Jack Black and Leighton Meester
Source
so, wtf?
en. wikipedia. org/ w iki/Sign_of_the_horns or Mano cornuta