A whistleblower is a person who provides information to law enforcement or regulatory agencies about a business that is engaged in suspected illegal or improper activities. To protect the public interest and encourage employees’ disclosure of illegal or unethical practices, Congress passed the Whistleblower Protection Act in 1989. The WPA allows employees to file a complaint against an employer if they think an employer is retaliating against them for disclosing improper activities, such as accounting irregularities or violation of an environmental protection law.