Patrick Byrne, a rare champion of cryptocurrencies among the heads of public U.S. companies, has stepped down from his roles at Overstock.com. Byrne wrote in a letter to shareholders Thursday that he was stepping down from the company both as CEO and as a member of its board of directors due to insurability and other reasons after admitting to a three-year relationship with Maria Butina, a Russian agent currently serving 18 months in prison after pleading guilty to charges of acting as a foreign agent. He will be replaced on an interim basis by Johnathan Johnson, the current president of Overstock‘s blockchain ... (full story)