I just saw on the news this morning, the same "chalk" incident happened somewhere in WI, "Jackson County", I never knew WI had a Jackson County. Anyway, about 9 kids were not allowed to walk or participate in graduation ceremonies. They were all yelling and protesting outside how unfair it was, and then a mom was interviewed and said, "these kids earned the right to graduate."
The principal said, the earned their diploma's, but they lost their right to the graduation ceremony.
A couple of years ago, kids cut evergreen trees down in Campbellsport WI. I think one was even the class President. 4 kids got caught, because others talked. He wrote an apology letter, etc, to papers, and they still wouldn't let him take part in the graduation ceremonies. He replaced the trees, he cut down, and the said part was, other graduation classes donated the trees a few years earlier.
I don't know what kids are thinking, but I feel, they want to leave a legacy or something. They really are not thinking, even though they have been told numerous times throughout the year, to not do student pranks.
I know some pranks are harmless, such as a group of students parked in the "workers" parking stalls on their last day. Got there really early and went to breakfast, then came to school. Other's do harmful things. But a prank is a prank, and administration (in our town) punishes everything the same.