Online social networks have gotten a lot more complicated since Facebook was just a college tool. Now the basic, joyful simplicity of keeping your friends in one place has developed all the complexity of real life -- you have to make sure Grandma is separated from Vinny the frat brother at all costs but everyone still wants to be friends. If we even have to create a "trusted friends" subset, it feels a lot like we've lost something important that the whole concept was originally meant to provide.