I have "my" profile on my computer with a separate password so no one can even get in to my email and bookmarks {forums}
and those each have a password too.
I am as admin on my computer so i only have full access all others are limited.

my hubby has his profile account {limited account}
daughter has her own {limited account}
and if the boys need to use it they are under family {limited account}

If i go away from computer for any length of time when others are at home I log off & go to the switch users screen and then re log on w/password.

Is yours set up with separate profiles?