That's what system administrators would always remind every employee.
A year ago, our company implemented electricity saving measures. It is mandated that we should log off our PC’s before going home so as to save up that extra cents from the company’s electricity bill. If you failed to comply, you will get a memo the following day.
As for me, it has always been my practice even though that measure is not yet implemented nor broadcasted. But, of course there will always be stubborn people who would leave their computers on. To resolve this problem, system administrators could make use of auto log off application. This application helps the administrators to define the maximum idle time or the time window when to log off a certain computer from the network. This useful application is very flexible; almost everything is set in its configuration. You can control a workstation from the network and have it automatically logout, restart, shutdown, or power down.