In recognizing if it is scam, asks some legal document to the group of people where they offer their product.
Don't invest to the company where the Founder or the creator of that group is hiding their real image or personality because absolutely they are the scammers.
I am not sure about this because as far I can see, many ICO give a real picture or maybe I cannot detect fake image for every people in the project. but this could be another option to detect the ICO is real or not and I think we can ask them about their project and what their vision with their project. I think if they are a good team, they will give information related to the project so people can know that there is a legit project and people could feel safe to join with them.