Cal. Pub. Util. Code § 5371.5
(a) Upon receipt of a complaint containing sufficient information to warrant conducting an investigation, the commission shall investigate any business that advertises limousine-for-hire or passenger charter transportation service for compensation in motor vehicles. The commission shall, in a rulemaking or other appropriate procedure, adopt criteria that establishes the type of information, if contained in a complaint, that is sufficient to warrant an investigation. Pursuant to this investigation, the commission shall do all of the following: