Technology or hacking is just the tool they use to do it. They will steal in other ways too. But even hacker magazines make strong voluntary rules that stepping over the line and becoming a bad hacker is not accepted. If you have rules like this and agree to them with other hackers, you abide by them. In my own computer classes we eventually get to client-server networking.
Every student has fun becoming a server, setting up various access privileges.
But I tell them that the rule is that anything you do to give someone else a scare has to be easily undone. They try to guess and figure out passwords and try to find inadequately protected machines in the classroom. Occasionally a student starts exclaiming that his or her folders are disappearing right off the desktop. I look around and see another student busy at the keyboard but smiling. In 9 years of class, all such violations have adhered to the rule of being easily corrected.