https://techcrunch.com/2017/11/20/tether-claims-a-hacker-stole-31m/

Bitcoin cruised past $8,000 for the first time this week, but it hasn’t been smooth sailing for all after Tether — a company that helps exchanges convert fiat currency to token — said today that a hacker snatched nearly $31 million.

Tether operates USDT, a cryptocurrency asset that it backs via the U.S. dollar. The company said that $30,950,010-worth of USDT was taken from its core treasury wallet “through malicious action by an external attacker.”