Wasn't the CEO but one of the co-founder that leaved with the money; second very bad stuff is that they had Bitconnet on their website when was acclaimed scam also from Vitalik and many others since the project's start.
you can check on waybackmachine or https://web.archive.org/web/20170504200205/https://mysterium.network/
For they modus operandi investors can start a petition

This project remind me bitconnect

Substratum was listed by several exchanges and with only 6 months the product was released for each OS, while mysterium?