Yes. We need to do some research at least at our level to keep ourselves away from such bounties. I am glad, I rejected a few and most of them turned out to be a scam project. It is very difficult situation when we worked for more than 4 weeks and in the end, we come to know that we haven't got any rewards or it was just a penny.
That's quite painful you know. Some people still say bounty hunting is an easy job, I bet they don't even know how that feeling is. Doing bounty campaigns is an easy task, it's true. However, it's not an easy task to be achieved. Old but gold sentence "do your own research". Always doing researches before joining in any campaign to reduce the risk of being scammed. You can eliminate the risks but you can reduce somehow, the better you are with knowledge, skills, and experience, the less risks you will face!