This case is interesting because even as the appellant claimed First Amendment protection, the appeal court did not review those issues de novo. Excerpt follows.
"B. Free Speech
Appellant contends the injunction is invalid because it violated his free speech rights.
The First Amendment to the United States Constitution and article I, section 2, subdivision (a) of the California Constitution both guarantee the right to speak freely. The right to free speech, however, is not absolute. (Near v. Minnesota (1931) 283 U.S. 697, 708; Aguilar v. Avis Rent A Car System, Inc. (1999) 21 Cal.4th 121, 134.) [T]he state may penalize threats, even those consisting of pure speech, provided the relevant statute singles out for punishment threats falling outside the scope of First Amendment protection. . . . A statute that is otherwise valid, and is not aimed at protected expression, does not conflict with the First Amendment simply because the statute can be violated by the use of spoken words . . . . (21 Cal.4th at p. 134, internal citations & punctuation omitted.)
Section 527.6 clearly is valid under this standard. The section makes it illegal to engage in a course of conduct that seriously alarms, annoys or harasses another person. ( 527.6, subd. (b).) The evidence here shows appellant engaged in such a course of conduct by repeatedly leaving abusive messages on respondents answering machine. That finding is not invalid simply because appellant violated the statute by using spoken words. (Aguilar v. Avis Rent A Car System, Inc., supra, 21 Cal.4th at p. 134.)"