Well for me before choosing a certain bounty program I consider some aspects that are very helpful in prohibiting such scam bounty campaign. First of all I check the bounty manager if the bounty manager have a high rank then I have trust on him/her secondly if the front page of their bounty program is attractive, we can say that they insert a lot of effort on it because they made the page very attractive so that they are willing in making the project productive and lastly is when the spreadsheet in updating we knew it was not a scam because they compute the stake week by week. I hope it might help you to consider such a good bounty campaign but at the end of the it is up to you on what bounty you've gonna choose.