Well, they seem nice...
I am always so baffled when things like this happen.
I try to imagine what kind of jolly someone gets out of it.
Is it a "true believer," bent on scaring people?
Is it a jerky kid, being a jerk?
Is it a combo of both? Something else?
Either way, It's stupid. And aggravating.
You have a bunch of kids heading straight into adulthood, on what should be a happy day...the first day at University. And some bonehead has to make it ugly. Bravo.