Ok, prefacing this: I don't use facebook, I dislike the website, I dislike the social implications of the website and I dislike the internal policies of the company in shit like asking people for ID.
BUT, quick reality check for a moment: for some people, "using facebook" is not a choice. I mean, it is ultimately a choice, just like wearing clean clothes is a choice or paying your rent is a choice. For some people, Facebook is the only channel of communication with some people they don't want to be separated from. For some, it's how they manage their social life, or there is some form of social pressure to use it and they're not in a position to say no easily.
And I'm sure if I don't add this little disclaimer, some pompous jerk will come correct me, tell me everything about how they were pressured to use Facebook but chose not to: Yes, you can do it, everybody can do it, but you're not in a position to tell other people how to live their lives when you are the person who knows the least about their lives. And funny that, THIS is the exact same problem GP quoted.
Facebook has a lot of power and that power is not being used responsibly. Defending that is appalling.
PS: This is not directed specifically to your post as I'm seeing this attitude in the entire thread. There's bubbles to pop here: Not everybody can just stop using facebook.