2. Anonymous project.
If you want to scam people, best way to do it is by hiding your identity. Therefore you should never trust a project that does not display its team members, company information nor physical address. No matter how good the project seems, there is a reason why they are hiding their identity.
This isnt always the case, I have always felt suspicious of ICOs when they link to the team members linkedin profile. Well, this may be legit in many cases as they want to build a positive trust by showing off the team. But, I also have seen people buying 20-25 old linkedin accounts through this forum.
Yes it's possible to buy fake account and scam people that way, this is why you should dig a bit deeper and check if they have any other social media profiles, or other online presence.
But anonymous team is still a very clear sign of a scam. Perhaps of a bad scam, since they didn't even bother to buy those fake accounts, but still a scam.