In this day and age it’s common for employees to use the printer for personal use, but the reason the usage never gets out of hand is shame.
Shame can be a great way to keep people in line at the workplace.
The boss doesn’t even need to be present for it to work. The potential threat of colleagues spotting an online shopping session can be guilt inducing enough to cut it short.
You could have finished all of your work, have nothing to do and still feel bad about leaving work early.
People often find looking busy more stressful then actually being busy. Which is probably driven by the shame of not working hard enough.
Thomas Duggan 