California Code, Vehicle Code - VEH § 21464

(a) A person, without lawful authority, may not deface, injure, attach any material or substance to, knock down, or remove, nor may a person shoot at, any official traffic control device, traffic guidepost, traffic signpost, motorist callbox, or historical marker placed or erected as authorized or required by law, nor may a person without lawful authority deface, injure, attach any material or substance to, or remove, nor may a person shoot at, any inscription, shield, or insignia on any device, guide, or marker.

(b) A person may not use, and a vehicle, other than an authorized emergency vehicle or a public transit passenger vehicle, may not be equipped with, any device, including, but not limited to, a mobile infrared transmitter, that is capable of sending a signal that interrupts or changes the sequence patterns of an official traffic control signal unless that device or use is authorized by the Department of Transportation pursuant to Section 21350 or by local authorities pursuant to Section 21351.

(c) A person may not buy, possess, manufacture, install, sell, offer for sale, or otherwise distribute a device described in subdivision (b), including, but not limited to, a mobile infrared transmitter (MIRT), unless the purchase, possession, manufacture, installation, sale, offer for sale, or distribution is for the use of the device by a peace officer or other person authorized to operate an authorized emergency vehicle or a public transit passenger vehicle, in the scope of his or her duties.

(d) Any willful violation of subdivision (a), (b), or (c) that results in injury to, or the death of, a person is punishable by imprisonment pursuant to subdivision (h) of Section 1170 of the Penal Code, or by imprisonment in a county jail for a period of not more than six months, and by a fine of not less than five thousand dollars ($5,000) nor more than ten thousand dollars ($10,000).

(e) Any willful violation of subdivision (a), (b), or (c) that does not result in injury to, or the death of, a person is punishable by a fine of not more than five thousand dollars ($5,000).

(f) The court shall allow the offender to perform community service designated by the court in lieu of all or part of any fine imposed under this section.