Facebook's apology-and-explanation machine grinds on, with The Social Network™ posting detail on one of its most controversial activities – how it tracks people who don't use Facebook. The company explained that the post is a partial response to questions CEO Mark Zuckerberg was unable to answer during his senate and Congressional hearings. It's no real surprise that someone using their Facebook Login to sign in to other sites is tracked, but the post by product management director David Baser goes into (a little) detail on other tracking activities – some of which have been known to the outside world for...