Is a defendant required to independently demonstrate that the issue is a "public issue" within the meaning of section 425.16, subdivision (e) of the California Code of Civil Procedure?

When the defendant's alleged acts fall under the first two prongs of section 425.16, subdivision (e) (speech or petitioning before a legislative, executive, judicial, or other official proceeding, or statements made in connection with an issue under review or consideration by an official body), the defendant is not required to independently demonstrate that the matter is a "public issue" within the statute's meaning. (Briggs v. Eden Council for Hope & Opportunity (1999) 19 Cal.4th 1106, 1113, 81 Cal.Rptr.2d 471, 969 P.2d 564.) If, however, the defendant's alleged acts fall under the third or fourth prongs of subdivision (e), there is an express "issue of public interest" limitation. (Id. at p. 1117, 81 Cal.Rptr.2d 471, 969 P.2d 564.)