Moon Zappa, daughter of the late singer-songwriter Frank Zappa, has applied for a restraining order against Mark Brownfield, who allegedly threatened her life (in a letter he sent to the FBI), reports the Associated Press. Brownfield had made claims that Zappa, 33, and her late father stole the lyrics of their 1982 hit song "Valley Girl" from him. After pleading innocent last month to making death threats against Zappa, Brownfield was nonetheless confined to a psychiatric ward in a federal detention center after a defense attorney told a judge that Brownfield had been diagnosed with paranoid schizophrenia and depression. Zappa's request for the restraining order extends to the protection of her mother, sister, two brothers and a male friend.