What is the test for a motion to strike against a person who acts in furtherance of their right of petition or free speech?

Section 425.16 provides... that [a] cause of action against a person arising from any act of that person in furtherance of the person's right of petition or free speech under the United States or California Constitution in connection with a public issue shall be subject to a special motion to strike, unless the court determines that the plaintiff has established that there is a probability that the plaintiff will prevail on the claim.' ( 425.16, subd. (b)(1).) As used in this section, act in furtherance of a person's right of petition or free speech under the United States or California Constitution in connection with a public issue includes[ among other things]: (1) any written or oral statement or writing made before a legislative, executive, or judicial proceeding, or any other official proceeding authorized by law; (2) any written or oral statement or writing made in connection with an issue under consideration or review by a legislative, executive, or judicial body, or any other official proceeding authorized by law....' (Id., subd. (e).) (Navellier v. Sletten (2002) 29 Cal.4th 82, 87-88 (Navellier).)