Yes, it actually difficult to identify scam projects however, for the benefits of the doubt, one of the best ways to know if a project is scam or no, is through the identify of the project TEAM.
The best protection against this fraudulent tactic is to thoroughly research the individual team members of a project before you invest. It's a bad sign, for example, if you're unable to find any information about a particular developer or founder on LinkedIn or other social media outlets. Even if profiles do exist, check to see if their activity seems to match up with the number of followers and likes they accrue. Individuals who rarely engage with their followers and yet have thousands of fans may not be real.