Yes I have. This was around October of 2017 where in I participated in this so-called project's signature campaign. I had a strong feeling that there was something fishy about the project. But I went on working on the campaign which ran for two months because the manager was really entertaining. He even went in saying that the project may be a scam and that we are working at our own risk. Well in the end, it was actually a scam. Fortunately I did not cash in and all I lost was my time. Honestly, It was a fun way of learning to be vigilant in choosing and dealing with these projects.
I think, that every bounty hunter have been scammed for once in their life. Especially, if bounty hunters participated in many social media bounty. As for me, I have been scammed for several times too