Does the trial court have a sua sponte duty to instruct the jury that "constitutionally protected activity" is a defense to stalking?

Appellant maintains the trial court had a sua sponte duty to instruct the jury that "constitutionally protected activity" is a defense to stalking. He claims this error constituted reversible error in that, had the jury been properly instructed, it could have found "that appellant's verbal expressions of hostility, namely, that he was going to 'kill' [his estranged wife], were incidental to his fundamental right to 'establish a home and bring up children," He believes Meyer v. Nebraska (1923) 262 U.S. 390, 399, supports his claim. Appellant contends that, properly instructed, the jury could easily have found that he was merely blowing off steam or expressing his anger during his court-ordered and constitutional right to visit his children.

Respondent believes the trial court properly instructed the jury regarding the offense when it utilized CALJIC No. 9.16.1 which, for the most part, tracks the language of the statute. Respondent cites People v. Poggi (1988) 45 Cal.3d 306, 327, for the proposition that the language of a statute defining a crime is generally an appropriate and desirable basis for an instruction, and is ordinarily sufficient in the absence of a request for amplification.

Respondent, relying on People v. Estrada (1995) 11 Cal.4th 568, 574, insists it was appellant's obligation to request any clarifying or amplifying instructions in the trial court. Having failed to do so, respondent asks that appellant be precluded from doing so for the first time on appeal. He cites numerous cases in support of this request.

Finally, respondent argues that, even if we were to find the trial court erred, it would be harmless under People v. Watson (1956) 46 Cal.2d 818, 836, since it is not reasonably probable a result more favorable to appellant would have occurred in the absence of the error.