Student Walks Away From Her Laptop at University

In the UBC Library, the signs say, "Don't walk away from your possessions because thieves will steal it."

So why would this student leave her laptop and books, to go to the washroom?

Perhaps it's because 9 times out of 10, her possessions will still be there.

Yet, I'm still mystified, because thieves still steal stuff from UBC employees when they leave the safe domain of UBC.