@Oasis11 - I understand what you are saying, but employees should know upfront that their calls and emails could be monitored. This way there is no excuse if they are caught sending personal emails on company time or making excessive personal phone calls.
It is important to use workplace monitoring software so that you can actually see where the employee is going when they log on to the system. There have been people caught accessing pornography sites which is highly inappropriate in the workplace.
I think that employees that know that they will be monitored and take the chance anyway have no one but themselves to blame. Internet monitoring is important because if people are surfing the web and not working they are going to hurt your business. Employees do have breaks that they can take when they want to make a personal call and that is the time that they should do it, not when they are working.