What is the biggest crypto scammer?

Excuse me, as a professional practitioner in the field of cryptocurrency and finance, could you please enlighten me on who the biggest crypto scammer is? I'm quite interested in understanding the individuals who have caused significant losses to investors through fraudulent activities within the crypto industry. Could you provide some insights into their modus operandi and the reasons why they were able to dupe so many unsuspecting individuals? Also, how can we, as investors, protect ourselves from falling victim to such scams in the future? Thank you very much for your time and assistance.