What is the best action if you know employees are stealing from the company?

Bringing the activity to the attention of management is the most appropriate action in this situation. Management is equipped to handle such issues according to company policies and legal requirements. Reporting the theft allows them to investigate the matter thoroughly, determine the extent of the problem, and take necessary actions, which may include disciplinary measures against the employees involved.

Furthermore, by notifying management, you help protect the company's interests and contribute to a healthier workplace environment. Ignoring the situation would not only be irresponsible but could potentially lead to further theft and financial loss for the company. While involving law enforcement might be necessary in serious cases, it is generally the responsibility of management to oversee internal issues like employee theft initially. Attempting to persuade the employees to stop their actions may not be effective and could place you in a compromising position.