Report them to the authorities, use social media to post warnings about the ICO and don't forget to provide concrete evidences to support your claims or create a website for posting the list of ICO's that are considered scams.
Won't work, scams are always vanish right after they been detected at scamming. Vanishing with all of your money by the way
I think we need better smart-contract protocols on blockchain platforms which host ICOs to better protect investors from total loss of funds. Like releasing of investors funds in phases: Q1, Q2, Q3 & Q4