Rapper Kevin Federline was met with a chorus of boos from a crowd in West Hollywood, California last night when he performed at the city's annual Halloween Carnival. Federline, who calls himself "America's Most Hated," was there to celebrate the release of his debut album Playing With Fire. Before he even began rapping his new song "Privilege," he was bombarded with jeers from the costume-clad crowd. Rumors circulated before his appearance that his wife, pop star Britney Spears, would be making a surprise appearance. According to entertainment news website Tmz.com, the crowd appeared to be let down after Federline performed one song and made a hasty exit to attend his album release party, driving off in a white Rolls Royce Phantom.