4. What are the principal objectives of the SEC's rules that require Form 8-K statements to be filed when public companies change auditors? Did Shepherd violate the client confidentiality rule when she discussed the United Airlines-Cardillo transaction in the exhibit letter she filed with Cardillo's 8-K auditor change statement? In your opinion, did Shepherd have a responsibility to disclose to Cardillo executives the information she intended to include in the exhibit letter?