K-Fed performs; and surprise! audience boos!

Kevin Federline calls himself "America's Most Hated" and last night he proved it, as his Halloween performance was met with a chorus of boos -- and not of the ghostly variety.

Before the first beat dropped from his new song "Privilege," Federleezy was bombarded with jeers from the costume-clad crowd at the West Hollywood Halloween Carnival. To his credit, the ratio of haters-to-fans hovered somewhere around 50-50, with at least half the crowd actually screaming in anticipation of K-Fed's performance.

Watch the video.

tmz