There are so many coins now that there are always teams that are not serious about technology. They just want to collect a sum of money, how to judge this is not a trustworthy team?
You can know about it by doing research about the project team if they don't have enough history then they maybe the scammers.But there are lots of new guys also creating good projects so we can't completely make a decision when some team don't have the history.So it is a little bit hard to know it is scam or legit that's why the ICO investment is called as risky.