hows hacking your own network (your schools, w/e) illegal?
it isnt. breaking into your own wireless is perfectly fine, as you are the owner of the network, and give yourself permission to do it.
therefore its authorised access, just in a wierd way
edit: ^ @cobra, im pretty sure chris could hack some wep. ive seen some of the stuff he does. whilst you were sat in the corner playing with your toys he was hacking into the play group server