I gotta admit that going to work in a big, shiny building in Los Angeles, wearing a shirt and tie, when I was in my twenties, was pretty overwhelming. I mean, I still thought of myself as that kid from high school, and maybe college, with paint on my nose from my art classes. But since I have a poor memory, I decided that I would be just one person, both professional and private.
I'm certainly not saying that you should go around giving out personal information. There are a lot of bad people out there. And they have been out there since before the internet. And it's never been a good idea to write your social security number on your backpack, or briefcase. But really, having people know that I own a dachshund doesn't seem, in my opinion, to interfere with people accepting that I am a college teacher.
So, if you're getting yourself all confused about Google+ circles, or privacy settings in Facebook, or exactly who you are in relation to someone else, my recommendation is to relax. And unless what you're doing personally is in direct conflict to what your professional life, don't worry about it. And if so, you may want to ask yourself why you are doing those things? I'm just sayin'.
Evaluate yourself. And if your professional image and your personal image are one and the same, chances are that you are on the right track.