California Code, Code of Civil Procedure - CCP § 2019.030

(a) The court shall restrict the frequency or extent of use of a discovery method provided in Section 2019.010 if it determines either of the following:

(b) The court may make these determinations pursuant to a motion for a protective order by a party or other affected person.  This motion shall be accompanied by a meet and confer declaration under Section 2016.040.

(c) The court shall impose a monetary sanction under Chapter 7 (commencing with Section 2023.010) against any party, person, or attorney who unsuccessfully makes or opposes a motion for a protective order, unless it finds that the one subject to the sanction acted with substantial justification or that other circumstances make the imposition of the sanction unjust.