18.11 Securities-Good Faith Defense to Controlling Person Liability is a legal defense that protects a controlling person from liability for the actions of other persons who are controlling or managing a company's securities. This defense is only applicable when the controlling person can prove that he or she acted in good faith and with reasonable care when they were making decisions related to the company's securities. This defense may also be used when the controlling person is accused of negligence in the management of the company's securities. There are two types of 18.11 Securities-Good Faith Defense to Controlling Person Liability: the business judgment rule defense and the due diligence defense. The business judgment rule defense applies when the controlling person can demonstrate that their decision was made in good faith and with the care of a reasonable person. The due diligence defense applies when the controlling person can demonstrate that they exercised reasonable care and diligence when making decisions related to the company's securities.