Reason 4: Your character
Torrenting and P2P file sharing is a choice. Nobody will force you to install the applications. You are responsible for what happens on your computer. If you make these choices, then you must be prepared to deal with the consequences. Repeated AUP violations tells everyone something about the choices you make. This information is documented in your school record and is viewable by teachers and administration.
Use your computer for good, not evil. Don't torrent.