First of all, I am going to say this out of experience and not from memes or from public opinion.
Two days ago, I changed a shortcut icon to redirect to another website on a school computer. Well, I got caught after someone fell for it, and then the teacher told me that I could get in serious trouble for it. He got some cops to tell me how bad it was, and afterward, I was wondering how stupid they were.
First of all, they said I shut down the system. I did not do that, I just changed the link.
Second, they said I was "scarier than a thug with a gun because I could hack their computers and get all the passwords". I can do no such thing, what makes them think that a simple prank automatically makes me a "1337 hax0r"?
Then they said I could be arrested for just that prank, but they decided to let me off because I was not aware of those rules.
Cops suck. (at least the ones in this area do)
EDIT- It seems like my email to the teacher completely backfired. The teacher COMPLETELY misunderstood the point of my message.