Some people stay logged in forever because they can. It's not the worst thing in the world but it definetly allows them to soak up SIC information. Why not have a nifty side effect to this?
I propose the fatigue script. If you fail to @quit for 6+ hours a day, you begin to experience. Go longer than 36+ hours without @quit for a reasonable amount of time and it gets worse, etc.
There could be stat debuffs to go along with it but I'd suggest they be minor at most.
LEGEND
