I was quite surprised by that claim too. I figured perhaps they had access to systems that let them check the FF status of the candidates. Wouldn't it be as simple as making a dummy booking, putting the FF number in and checking what status shows up on the record? agents must be able to see the status to see whether they can assign seats and what luggage allowances are. Other airlines in the alliance can certainly see what status is attached to a record so it wouldn't be a stretch if other GDS users could see as well.

But apparently that's just not the case or if it is they don't make any effort to use data like that.