If you are truly concerned about harm to users, did you try reporting this to facebook.com/security or facebook.com/whitehat? FWIW, I've alerted some people.
Your post is unclear on one point. Did you see this screen BEFORE confirming via SMS that you were in possession of the mobile number you entered? If it was after confirmation, that's a very different thing.
Your post is unclear on one point. Did you see this screen BEFORE confirming via SMS that you were in possession of the mobile number you entered? If it was after confirmation, that's a very different thing.