Be careful and read more about the project before you invest or join in any bounty. It is much important to read first and learn how the project really works.
In case of bounty, we only lost our time. But if we invest in the ICO, the worst is that our money is not doubled, our money can just disappear. No one can't just join without reading anything. Learn the project, then do invest after that.
Well, a lot of precautions out there that we need in order to prevent ourselves from scammers, we also have our own knowledge and we can feel strange feeling if something is wrong that is why we need to be careful with everything that we are doing so the scammers will be having a hard time making money.