The biggest crypto crime and the on that i think has changed the course of any investment on the internet is the ponzi scheme made by one coin site where they have walked away with more than 667 million dollar, onecoin claimed to be the bitcoin killer, that many people believed it and they invested their money their saving only to wake one day and find out they have have been scammed, to this day the founder is still on the run and the case is still not solved, with the one coin scam everyone lost their trust in these types of companies and projects.