The one thing I don't like about using Facebook (or similar sites) for commenting on sites like TechCrunch is that my Facebook friends couldn't give two hoots in hades about my "tech world" blabbering. For them it's mostly irrelevant.

I don't use Facebook as a business networking tool -- I use LinkedIn for that -- instead I just use it on a purely social level and I don't really want the two to mix.

Business and social don't need to mix in order for you to be authentic.