It can only be 2 accounts active at the same time. It used to be up to 5 but Sony updated the console from preventing so many people to game share.
And I hate 'em for that.
I would gameshare only to the people that I've met before. If you give your account to the wrong person, then say goodbye to your PSN account.
I wouldn't even gameshare with my own brother whom I trust 100%. And he's got PS+ and tons of great games purchased on his account.
Why not? I do that with mine. And we agreed that we'd split the PS+ costs. After all, it wouldn't be fair if he was the only one paying for it.
I mean, do you REALLY think that your brother would be so rude that he'd start messing with your account?
Also, I'm not that scared about gamesharing, and getting my account stolen. I would gameshare with few of my RL friends if we had the old 5 system limit.
Actually, I'd even share with few of my PSN friends that I haven't even met IRL. Well, I actually tried that long ago (and I'm still here right? ) but that was around the time they changed it to two systems.