This is basically just aggression, if we're honest.
It's perfectly normal to assault your roommate because she ate your thin mint Girl Scout cookies, right? No? Here are some people with Hulk-like anger that you probably shouldn't tick off. (Or else).
Maybe this is a standard practice I don't know about, but Jesus.
Aggressive-aggressive notes are the new broom handle to the ceiling. (Via Passive Aggressive Notes.)
Ah, the finest the angry-note genre has to offer.