IM belongs to the employer, not the employee. Use written policy to notify employees that the computer system as a whole, including the IM system, the messages, and user IDs, belong to the organization, not the individual. Clarify that the organization has the right to access and review the content of any instant message that is created, stored, transmitted, or received using resources provided by the company. If you allow the use of personal IM clients, let employees know that these messages are subject to monitoring, too.