California Code, Business and Professions Code - BPC § 22961

(a) No person, firm, corporation, partnership, or other organization shall advertise or cause to be advertised any tobacco products on any outdoor billboard located within 1,000 feet of any public or private elementary school, junior high school, or high school, or public playground.

(b) This section sets forth minimum state restrictions on the advertisement of any tobacco products on outdoor billboards near schools and public playgrounds and does not preempt or otherwise prohibit the adoption of a local standard that imposes a more restrictive or complete ban on billboard advertising or on tobacco-related billboard advertising. A local standard that imposes a more restrictive or complete ban on billboard advertising or on tobacco-related billboard advertising shall control in the event of any inconsistency between this section and a local standard.

(c) This section shall not be construed to prohibit the display of a message or advertisement opposing the use of tobacco products. However, this subdivision shall not be construed to permit an advertisement promoting the use of tobacco products by including a message opposing the use of tobacco products within that advertisement.