California Code, Civil Code - CIV § 1812.521

(a) No job listing service shall, when employment would be in violation of Chapter 1 (commencing with Section 1171) of Part 4 of Division 2 of the Labor Code or Part 27 (commencing with Section 48000) of the Education Code, accept any application for employment made by, or on behalf of, any minor, or place or assist in placing any minor in that employment.

(b) Every job listing service shall notify each jobseeker before sending the jobseeker in response to a request for employment whether a labor contract is in existence at the establishment to which the jobseeker is being sent, and whether union membership is required.

(c) No job listing service shall send a jobseeker to any place where a strike, lockout, or other labor trouble exists without notifying the jobseeker of that fact and shall in addition thereto enter a statement of those conditions upon the contract or receipt given to the jobseeker.