Why do some times they ociate the horn hand sign with the Devil?

And some times they ociate it with rock and roll. Is it to say the Devil rules rock and roll? American Idol had a lot of that sign when it was bonjove night last night. To me it is afiliation with Satans Secret Underworld Society 666. Hay check that out would you. "Satans Secret Society" "666" sounds alike doesnt it? I thought old George bush was going to start flashing his sign around up there also. I've seen pictures of him and his wife flashing that sign New World Order. When he talks about God what "God" is he talking about?