Still, it's worth doing, if he/she knows your password, they can change your password, plus, they could download everything you've bought from the Store meaning you'd get less downloads for yourself... But I guess it's your loss. :l
He only signed in once and it was for a few seconds and that was days ago so im not worried about anything. I dont have a credit card hooked up to my PSN and I can remember all the friends I want on my friendslist so im not worried at all
Hey, if some mysterious person is on your PSN account, I'd change your password from the official PlayStation site, and I'd do it quickly...
