It is embodied in their Code of Civil Procedure
Here is the text of the statute:
425.16. (a) The Legislature finds and declares that there has beena disturbing increase in lawsuits brought primarily to chill thevalid exercise of the constitutional rights of freedom of speech andpetition for the redress of grievances. The Legislature finds anddeclares that it is in the public interest to encourage continuedparticipation in matters of public significance, and that thisparticipation should not be chilled through abuse of the judicialprocess. To this end, this section shall be construed broadly. (b) (1) A cause of action against a person arising from any act ofthat person in furtherance of the person's right of petition or freespeech under the United States or California Constitution inconnection with a public issue shall be subject to a special motionto strike, unless the court determines that the plaintiff hasestablished that there is a probability that the plaintiff willprevail on the claim. (2) In making its determination, the court shall consider thepleadings, and supporting and opposing affidavits stating the factsupon which the liability or defense is based. (3) If the court determines that the plaintiff has established aprobability that he or she will prevail on the claim, neither thatdetermination nor the fact of that determination shall be admissiblein evidence at any later stage of the case, and no burden of proof ordegree of proof otherwise applicable shall be affected by thatdetermination. (c) In any action subject to subdivision (b), a prevailingdefendant on a special motion to strike shall be entitled to recoverhis or her attorney's fees and costs. If the court finds that aspecial motion to strike is frivolous or is solely intended to causeunnecessary delay, the court shall award costs and reasonableattorney's fees to a plaintiff prevailing on the motion, pursuant toSection 128.5. (d) This section shall not apply to any enforcement action broughtin the name of the people of the State of California by the AttorneyGeneral, district attorney, or city attorney, acting as a publicprosecutor. (e) As used in this section, "act in furtherance of a person'sright of petition or free speech under the United States or California Constitution in connection with a public issue" includes:(1) any written or oral statement or writing made before alegislative, executive, or judicial proceeding, or any other officialproceeding authorized by law; (2) any written or oral statement orwriting made in connection with an issue under consideration orreview by a legislative, executive, or judicial body, or any otherofficial proceeding authorized by law; (3) any written or oralstatement or writing made in a place open to the public or a publicforum in connection with an issue of public interest; (4) or anyother conduct in furtherance of the exercise of the constitutionalright of petition or the constitutional right of free speech inconnection with a public issue or an issue of public interest. (f) The special motion may be filed within 60 days of the serviceof the complaint or, in the court's discretion, at any later timeupon terms it deems proper. The motion shall be noticed for hearingnot more than 30 days after service unless the docket conditions ofthe court require a later hearing. (g) All discovery proceedings in the action shall be stayed uponthe filing of a notice of motion made pursuant to this section. Thestay of discovery shall remain in effect until notice of entry of theorder ruling on the motion. The court, on noticed motion and forgood cause shown, may order that specified discovery be conductednotwithstanding this subdivision. (h) For purposes of this section, "complaint" includes"cross-complaint" and "petition," "plaintiff" includes"cross-complainant" and "petitioner," and "defendant" includes"cross-defendant" and "respondent." (i) On or before January 1, 1998, the Judicial Council shallreport to the Legislature on the frequency and outcome of specialmotions made pursuant to this section, and on any other matterspertinent to the purposes of this section. (j) An order granting or denying a special motion to strike shallbe appealable under Section 904.1. (k) (1) Any party who files a special motion to strike pursuant tothis section, and any party who files an opposition to a specialmotion to strike, shall, promptly upon so filing, transmit to theJudicial Council, by e-mail or fax, a copy of the endorsed-filedcaption page of the motion or opposition, a copy of any relatednotice of appeal or petition for a writ, and a conformed copy of anyorder issued pursuant to this section, including any order grantingor denying a special motion to strike, discovery, or fees. (2) The Judicial Council shall maintain a public record ofinformation transmitted pursuant to this subdivision for at leastthree years, and may store the information on microfilm or otherappropriate electronic media.