Still not 100% clear what the issue is...
Is it:
1) folks creating new FFNs/accounts with their information and then signing up for the cards to receive the bonus across many FFNs/accounts...
or
2) folks creating new FFNs/accounts with ficticious information for the sole purpose of generating mailers/emailers and then using their own/primary FFN in the application so that all the bonuses accumulate in a single FFN/account?