If he does keep the computer make sure you cover your login passwords or something. Changing or making it where you have to login every time you go to the site.
I don't know much about computer security but if he doesn't know much than that should sufice.
You wouldn't want him posting as you and get you banned if he's the type to do it.
again, good luch.
-------------------- Life is but a memory on the breath of a dying man.