How about we attempt to picture. When you contribute an ICO like you contribute to purchase the coin or token of that ICO. They pay to you by their coin or token. On the off chance that their task have a magnificent achievement, the cost of token or coin is flying, you can take your benefit. On the off chance that it's come up short, I think they have no obligation to pay you. In this angle, i'm simply taking about genuine ICO, not trick. In the event that they need to trick, there are a ton of thing to discuss that
From my experience with Centra Tech then the even though the ICO was successful (based on their statements) they failed to pay the bounty participants and by this I was scammed too, then I received negative feedback because the centra tech team hadn't paid the participants even though it was not my responsibility but I understand how the DT members play with others especially those that want to take the job in every bounty then I understand that they want to eliminate the competitors (in this case me and many others)