Do you think it is a harmless prank to mess with another persons account? What would you do if you find a computer was left on and accounts were not logged out?  What would you want someone to do if you left your computer on and accounts open?

Yes, I think it's harmless to mess with other persons account. I think it is just fun to pull a little joke on them. It is our friend and we are just playing a joke on them. It not meant to be hurtful it was meant as a joke so we could get a few laughs.