Fortunately, I am yet to be stung by ICO's not paying out after investment, but I can understand the frustration, as I have been scammed in other ways (producing designs and not being paid).
Unfortunately, there is not really much that can be done, or at least that is my understanding, you just have to be as careful as possible and do as much due diligence as possible before investing in any ICO.
I know this might not help much, but we have all been burnt before and hopefully, it doesn't happen again.
Honestly, anyone who is smart enough to not just invest in any ICO but do proper research hardly get burnt by ICOs. One do not need soothsayers to tell someone that scammers and plenty of them are out there on the loose. You just have to take precautionary measures and not just look at the graphic designs, the English in the white paper and so on. The team is very important and how feasible the project is.