You make some good points, but I think there's a difference between having a few personal details about someone and surveillance. The clincher with Facebook is the amount of detailed information about the time and place that you are doing things, all in the hands of a single private entity. There's no telling what kind of analysis this data gives them and perhaps law enforcement (if not today, tomorrow?). For example, a few weeks ago there was a post circulating about how FB inferred the location of a photo without any location information in the exif data. Even if you use their ever-changing privacy controls to hide your data from people you don't know, Facebook still has access to all of it.
