Bitcoins and other cryptocurrencies have carried a reputation as anonymous conduits for illicit transactions, especially on the dark web. But recent federal cases show that the same financial instrument that keeps online black markets in business is also their Achilles' heel.
Individuals who charge a fee to exchange bitcoins and other cryptocurrencies for government-issued banknotes must register, comply with anti-money laundering rules and report suspicious transactions, same as any company, according to the U.S. Treasury Department.