I used to maintain a college computer lab for a living, so I know how quickly printer costs can add up.
Personally, I didn't really care if students hogged the printer for an hour printing a 500 page book, because I had a printer of my own at home. What DID bother me, however, is that total print costs were split up, and added to the next semester's computer lab fee.
So, EVERY time some moron decided to print an entire 100 page article instead of printing the two pages that they needed, it ending up adding a few cents to everyone's tuition bill.