If you care about your campaign, maybe you should limit the criteria of Newbie accounts that apply. Even newly created accounts you accept, it's like you intentionally attract cheaters to participate in making your campaign successful.
Some bounty managers seem to also apply restrictions at least for the amount of activity from Newbie accounts. It might help a little to reduce woke up accounts and new accounts to apply. But it will not be effective enough to reduce the greed of cheaters. They will only need more effort to adjust their accounts to be able to apply for campaigns.
is to add an extra challenge by requiring at least 6-8 posts spread throughout the past week before they can apply or be accepted. This will take effect next week. This way, cheaters will likely lose interest in exploiting the campaign, and if they still attempt it, the effort required wouldn’t be worth just $5-$7.
Hope you succeed in your way. But as I said, it will just take a little more effort on their part. Some of the accounts mentioned above seem to be only for your review campaign. Now those cheaters will just create new accounts and spam POA in the bounty thread and they will be eligible to apply for your review campaign with their new addresses.