I can't find any information on the web at all about this subject. So is it possible to power on a computer via a USB keyboard? I have done it with ps/2 but can't find any information about usb.

The problem is I need to find a way of stopping them from turning off the computers with the power button, the only thing I can think of it unplugging it and making them turn on via the keyboard (and wol but that isn't any good in the middle of the day).

What do others do?