CA AB523

Prohibits mobile telephony service providers and their affiliates or agents from disclosing a subscriber's historical, current, or prospective cell site location information without first obtaining express consent from the subscriber.

Establishes limited exceptions to the cell site location disclosure restriction for 911 emergency calls, imminent threats to life or property, and court-ordered warrants.

Requires express consent for cell site location disclosure to be obtained through either a separate signed document or a separate website field with no default option, with clear disclosure of what information will be shared and to whom.

Exempts from California Public Records Act disclosure requirements records of cell site locations obtained by law enforcement, fire protection, public health, and emergency services agencies.

Makes legislative findings that protecting subscriber privacy interests in cell site location data outweighs public access interests under the California Constitution.