That means a lot of trust in what they are doing and that they will not attempt do abuse their powers, considering the decision used to be held only by a federal judge. Computers we use for our day to day activities, at school and work places are connected to a lot of other systems on a network and we can be observed by anyone. This is as a result of security concerns. Employers are not only concerned with productivity drain, but also security issues. Employees might be forwarding confidential information outside the company.
Companies take increasing measure to protect themselves because of fear of lawsuit.
They do so by monitoring employees email so as to discover and prevent any workplace abuse. Most companies do not. Few have formal policies on workplace use of email and the internet. We can protect ourselves by using our common sense. This article provides some good ideas for protecting ourselves if we don't want our privacy to be invaded.