What is the appeal of hacking?

I can understand why someone would try to hack into financial institutions to gain money, or to create something like wikileaks to gain information.

But it seems that a lot of recreational hacking happens. I just got an email from my school’s IT department that we can no longer use a remote desktop connection to access computers at school while off campus because there have been too many hacking attempts.

As far as I can tell the purpose of this hacking is solely to cause problems and inconvenience other people. Not to mention the lunatics who want to shut down facebook. I have trouble thinking of analogous behaviors that have so little reward for the person doing it, and so much cost to other people.

Is there some hidden benefit I’m not seeing? Or are these people just sociopaths?