Sienna Miller has reportedly hired two bodyguards to protect her from a transvestite stalker. The actress has become nervous about the crazed fan after he sent her a string of bizarre letters. A source tells Britain's Daily Star newspaper, "In his letters he talks about being obsessed with her look. He tries to follow her everywhere. "The poor girl hasn't been sleeping properly because she has been so scared. Things just got to the point that she just had to take extra care of herself." The transvestite, called PETER, is said to be obsessed with Miller's look as Andy Warhol muse Edie Sedgwick in new movie FACTORY GIRL.