"Minor vandalism" in this sense is things like writing on desks and walls, writing in books and things of the like. It never really annoyed me until now, when I saw a particularly large amount of it today at school. I can't believe some people would just randomly write in other people's things, like this picture.

If you can't read it, it says:
First name: Ca$h
Last name: Money
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Discuss, I suppose.