Have we made our employees’ contact info too accessible?

Q: “We have created an employee directory in Outlook that contains employees’ personal information (home phone, cellphone number, address). This directory is for internal use only and only current employees have access to the directory. One of the employees expressed displeasure with having personal information available to all employees. Is there any legal issue with us posting their personal information in this directory? Do we need to get employees’ permission?” – JMG, New Jersey