I'm not a hugely private person, but most of my posts here are limited to my circles. Public posts that I do make are likely to be about my band, math, education, or gay rights issues.
If I don't already know you, or have at least interacted with you via a mutual friend, I'm not going to add you back. If you add me and I don't add you back relatively quickly, it means I don't recognize you. So, if I actually do know you somehow, you probably should refresh my memory.
My profile drawing is by John Wolfe, http://jcwolfe.deviantart.com/