An anonymous reader writes "My Health Sciences Campus has about 8,000 desktop computers, and on any given night about half of them are left on. I know this because I track all the MAC addresses in case there is a virus outbreak. Aside from the current fad of 'being green', has anyone had any success in encouraging users to power-down at night? You could potentially eliminate running bots, protect yourself from the next virus outbreak, keep your data safe, etc. Do security concerns and power consumption issues matter enough to do this?"