Whatever you do, do <i>not</i> punish him for this. While what he did was not right (though your use of "hacking" here is very broad), instead of telling him how wrong it was, simply try to push him in a more positive direction. My suggestion would be to ask him to work on some sort of project for or with you, perhaps even get him involved in something small and open source. Starting a website may even push him in the right direction.<p>An alternative would be to talk to the school and see if they could give him some sort of credit for helping administer the network, or work on a special project for the school.<p>To give you an anecdote: in high school (and this was only a few years ago), me and my friends consistently were cracking passwords and breaking into various parts of our school's network. We never did anything harmful, nor did we ever cheat, but we did it for the fun and the challenge. One day, we happened to find a file containing all the passwords to every user on the network -- teachers, guidance counselors, and principal included -- and we turned it into the principal. Instead of telling us we were wrong for "hacking the network" and questioning us, he thanked us profusely and got the file deleted from the network. No punishment.<p>In middle school, however, I got in minor trouble for "hacking" by using proxies to skirt around the school's filtering system. The "techs" in the computer lab quite literally pulled me out of class and angrily questioned me, telling me how I was wrong and what I did was bad. What happened? I continued doing it, and just made sure not to be caught.<p>My point is that telling him he is wrong will not stop him, and he will likely continue what he is doing because it stimulates him and he finds it exciting. By nurturing that excitement and funneling it into something constructive, such as an alternative project, he will learn what the better avenues are and likely forget about "hacking"/cracking almost (if not) completely.