#1? I don't think that they're doing anything related to what the investors do aside from investing their time to promote crypto. Consider also those bounty hunters that don't do anything but just keep on relaying their personal info for the airdrops.

#2? They're just mostly dumpers that would sell their coins, there comes the risk of the bounty coin they're holding would just drain out into zero after a day so mostly they're dumpers. I don't know how could they be scammers though.

You can never stop those bounty hunters from joining bounty campaigns, because their only sole purpose to interact with the ICO they're interacting at is to earn money, which is not different from the aim of others to just simply get rich really as fast as possible.