Quite difficult to actually determine. Even Bittrex, such a large stock exchange with a reputation could not recognize the RAID scam. Although everything seems to be on their site is beautiful, a lot of partnerships, team experience and everything seems to be good for the standard ico selection points.
for now there is no sure way to find out whether the ICO is a scam or not because the fraudsters also start cleverly hiding their crimes.
and sometimes ICO is actually not cheating but the team cannot develop the project so the project is scam and such things are very difficult to predict.