Criminal charges against a Russian man who allegedly used stablecoins to help his countrymen evade U.S. sanctions highlight the concerns about the cryptocurrencies, just as Congress considers legislation to regulate and legitimize them. 

Iurii Gugnin, who went by George Goognin, started a fintech company called Evita to help customers move money across borders, including through the use of stablecoins. Through that network, prosecutors say, Gugnin helped foreign customers move roughly $530 million into cryptocurrency wallets and U.S. bank accounts, including from sanctioned Russian banks.