Cal. Elections Code § 2138.5

(a) Notwithstanding any other law, an affiant’s driver’s license number, identification card number, social security number, and signature contained on an affidavit of registration are confidential and shall not be disclosed by an individual or organization that distributes voter registration cards pursuant to subdivision (b) of Section 2158, or by a person entrusted with an affidavit of registration from an elector pursuant to paragraph (2) of subdivision (b) of Section 2158. However, this subdivision shall not be construed to prohibit a person entrusted with an affidavit of registration from an elector pursuant to paragraph (2) of subdivision (b) of Section 2158 from returning the affidavit to the individual or organization that distributed the voter registration card pursuant to subdivision (b) of Section 2158. (b) An individual or organization that distributes voter registration cards pursuant to subdivision (b) of Section 2158, a person entrusted with an affidavit of registration from an elector pursuant to paragraph (2) of subdivision (b) of Section 2158, or an individual or organization that assists with the submission of an affidavit of registration electronically on the Internet Web site of the Secretary of State shall comply with both of the following: (1) Shall not use affidavit of registration information for any personal, private, or commercial purpose, including for any of the following: (A) The harassment of a voter or voter’s household. (B) The advertising, solicitation, sale, or marketing of products or services to a voter or voter’s household. (C) Reproduction in print, broadcast visual or audio, or display on the Internet. (2) Shall employ reasonable security measures, including employing administrative and physical safeguards, and, for affidavit of registration information available in an electronic form, technical safeguards, to protect the voter registration information from unlawful disclosure and misuse.