Yes,it is a common scam. Scan for bookings with no FFP, insert FFP number linked to an account you have. Then sell the miles/ tickets by adding people to redemption group. It is how many of those 'buy business ticket cheap' shops operate

Used to be most prevalent on Korea/ China flights (for all airlines) as so many people with same surname, so could set up "A Kim, B Kim, C Kim" accounts. Name/ DOB/ 2FA matches have become more stringent by airlines over time, but still can happen. OTA/ call centre staff will be running robots searching for names/ no FFP that match.

The staff involved think it is 'victimless' as the airline "would have paid the miles out anyway"