An unauthorized tell-all biography of media mogul Oprah Winfrey contains details so shocking, the author claims she has been blackballed from appearing on most major media outlets. Kitty Kelley, famous for her unauthorized biographies of American icons including Frank Sinatra, Elizabeth Taylor and Nancy Reagan, is back at it again with her book, “Oprah.” And Kelley says the salacious details -- from Winfrey’s "concocted" stories about childhood poverty and abuse to tales of secret lesbian affairs -- could do so much damage to the talk-show host’s image that her high-powered media pals, fearing alienation, don’t want to come anywhere near...