You don’t need a law to ask someone for their password. I can ask anyone for their password to anything. I can ask you for the key to your house. The problem is, some 8th grader isn’t going to know that he can refuse when he has the principal and his homeroom teacher staring at him and he knows he sent those nasty private messages. He doesn’t know he’s allowed to say ‘no, I don’t have to give you my password, call my parents’.
It reminds me of when I watch an episode of Cops and they pull someone over for something silly and they cop says ‘mind of I search your car for drugs or weapons’. It seems that often times the guy will say ‘well, you’re gonna do it anyways so go ahead’. I always thing the cop should have to say ‘Can I search your car, keep in mind that at this point you do have the right to refuse to allow me to search your car’. Not that it matters since they’ll find a reason anyways, but still, most of those guys don’t know that they CAN refuse.
Similarly, some kid doesn’t know that he CAN refuse to turn over his password. He might not even be smart enough to know that if he didn’t do anything wrong this would be a great time to say ‘I’m not giving you my password, but I’ll log on and let you can poke around so I can clear my name’ whereas a guilty kid might not be smart enough to shut his yapper and get his parents down to the school.
Now, having said all that…When Kenny says “Look Mrs Jones, here’s the messages that John sent me” and John sits there with his mouth shut and won’t work with the school, that’s when it’s time to just hand it over to the local police and let them deal with it (assuming it’s that bad). Again, no he doesn’t have to hand over his password, but in some cases it may be in his best interest before he ends up with cyber-bullying on his record.