read thier white paper and check the website if that ico is really promising and profitable in the future before o invest it. we cannot identify which ico is leget or scam so we have to do is do a reasech abot the ico before we invest.
There are of course promising ICOs around but finding them (the legit one) is not an easy task because there are other scammers who know how to play and deceive people. But all we can do is do a deep investigation first as to their team, their whitepaper, the roadmap, (if all of these are realistic enough) and of course the concept of the ICO.
Nowadays, the concept about trust in ICO is worthless. In my opinion, you just need to invest which project has hype and many investors. Then, after list on exchange, you can sell with fast profit and go to other projects, unless you can buy this coin at low price (after listed on exchange in short time).