Yeah, these still exist, though they're becoming more rare. I think what you actually want though is for processes to be killed at the end of class/lab period (even then, I think this should be done by students manually to avoid losing unsaved work). For example, say a student is running some big batch job as part of a lab. Now, if he wants to, say, go to the bathroom or go to the whiteboard to consult with other students, he has to either leave the computer unlocked (possibly leaving neighbors access to private student account data) or kill the running job.