The only way to stop this abuse is by having bounty ty hunters actually pm the manager verifying they are joining the bounty. The proof of authentification does not work anymore.
At least by having each member pm you to claim a spot in the bounty, you know you're getting the real account in the bounty and paying the correct person.
An easy solution, which I've been suggesting for quite a while, would be to scrape the ETH-address from the Location field in the user's Bitcointalk profile. Or a Bitcoin address if needed.
The "proof of authentication" is unnecessary bump spam. I still don't really get why this is even allowed. Scraping an address from a user's profile can even be done by Google Sheets, and this would ensure nobody can get paid to an address not used by a certain Bitcointalk account.
Its alot of extra work for managers so I doubt that most will adopt the correct way of doing things.
Even worse: it's counter productive for them. More spam means more earnings, and fighting spam means spammers start complaining while the real participants for some reason don't complain about losing their fair share.
From what I've seen for the few bounty campaigns I've managed, about 1% of the contributions are what I call quality. The rest is useless spam and/or plagiarism.
Accounts of criminals against other members' profiles.
I think you're wasting your time hunting down and tagging spamming Newbies. I have no doubt there are at least tens of thousands of accounts like that, and it takes zero effort for them to create many new accounts.