I agree with you mate. Their social media campaign full for only a minutes, or an hour. How they do that? Maybe if the maximum participants is 3500, 500 are real, 3000 are themselves, bountyhive team.
Anything can happen but those shady acts aren't acceptable and I heard that majority of the allocation goes to their pockets and their poor participants left wondering. However, in the end of the day, we should join our own risk so if you think that they're up to something fishy then stay away from it and look for some decent bounty campaign. Better to join in some freelance manager that have a good reputation either.