Almost all of the Bounty right now is a scam, you will only know that it's a decent one until they give you your fair share for doing bounty with them. Before joining a bounty you will even if you do a research about the company and the project it will still not be enough to trust them to give you a share since most scam company now has a legit look over the companies overview and roadmap.

It's not safe to join a bounty program for your effort will be just for nothing.