Downright sinister, isn't it? The vile cult of Scientology does this too, look how that works out.
FB alleges they collect data for purposes of advertising or directing relevant links...for their profit, btw. One can only suspect what devious purpose(s) might lie unsaid, or who is covertly exploiting this data. FB has become detrimental to our society in my view, too many trolls, bullies and predators, too many fools inviting peril on themselves.