that's a problem is very annoying better you report to Moderator or posting in Meta and hope that's account could be banned
They cannot be identified as they register with OTHER PEOPLE'S accounts and also use new just created Ethereum addresses with no transaction history, so it's impossible to ban them, as we just don't know who they are. The only thing we can do is to ask a bounty manager to delete them and not to pay them, so this is how we can make their business less profitable, so one day they may just stop.