Can a witness refuse to produce evidence in a civil proceeding?

A fundamental principle of the common law is that "`"the public ... has a right to every man's evidence." (Trammel v. United States (1980) 445 U.S. 40, 50, 100 S.Ct. 906, 63 L.Ed.2d 186). Under California law, if good cause has been shown for the production of a writing in a legal proceeding, no person has a right to refuse production of the writing in the absence of a statutory privilege permitting such refusal. "Except as otherwise provided by statute: [] . . . [] (b) No person has a privilege to refuse to disclose any matter or to refuse to produce any writing, object, or other thing." Evidence Code section 911 subdivision (b).