Do You Ever Actually Sign In With Facebook?

When that little blue "Sign in with Facebook" button first appeared, it was a little creepy. We don't want Facebook to know about every single service or app we're using online. Well, it turned out to be an amazingly convenient tool for some of us. No more forms!

But, uh, it seems like using Facebook to log in to a job search site might not be the wisest move for your career. If that's the case, where do you draw the line? Do you ever actually sign into online services with Facebook?