I've come across a type of scam where someone on a dating app like tinder will pose as an attractive person with the intention of trying to convince the victim to engage in sexually explicit texts or snapchats. Once they do, the scammer then looks up the friends of friends of the facebook profile associated with the number and then tries to blackmail the victim with threats of sending embarrassing texts to their closest friends. There are now TV commercials warning about it too. The best thing you can do is beg the scammer to post the texts, it really confuses the hell out of them and thanks to this facebook feature, the threat is greatly minimized.