Leaving Incriminating Evidence
Usually, when you vandalise something, you don’t want people to know where you, the vandal, live. But this kid didn’t have any idea what they were doing. They merely wanted to give their friends the right directions to their apartment… by scribbling arrows on the apartment hallway walls.
Their parents weren’t amused because A) you drew on the wall, which your parents taught you not to do before you went to kindergarten, and b) they had to pay to paint over your helpful directions. Writing tiny letters is bad enough but making them two feet tall? Sorry, kid, but you were asking for a spanking.