Cal. Bus. & Prof. Code § 5463
The director may revoke any license or permit for the failure to comply with this chapter and may remove and destroy any advertising display placed or maintained in violation of this chapter after 30 days' written notice is forwarded by mail to the permitholder at his or her last known address. If no permit has been issued, a copy of the notice shall be forwarded by mail to the display owner, property owner, or advertiser at his or her last known address.
Notwithstanding any other provision of this chapter, the director or any authorized employee may summarily and without notice remove and destroy any advertising display placed in violation of this chapter which is temporary in nature because of the materials of which it is constructed or because of the nature of the copy thereon.
For the purpose of removing or destroying any advertising display placed in violation of this chapter, the director or the director's authorized agent may enter upon private property.
Ca. Bus. and Prof'l. Code § 5463