If you ended up joining a scam bounty campaign, I think it's your fault because you do not do your research on the project and the bounty manager. You can try to follow an experienced member or a Hero member here if in a bounty campaign has a lot of high ranking members then possible that the project good and profitable. I think there are a lot of ways to check the project if it's legitimate or not, but the easiest way is to copy the other members.