Bitcoin for free?

Users could obtain Bitcoin worth trillions of dollars for free on Zaif, a Japanese government-registered cryptocurrency exchange. The 18-minute long glitch happened on Feb. 16 and was reported 4 days later by the company. 

7 customers got to purchase the lucky coins for 0 yen, and one of them attempted to sell ones worth ¥2,250 trillion — approximately $20 trillion, but the exchange managed to cancel all illicitly-gained transactions. 

The glitch drew a new wave of attention to security systems at cryptocurrency exchanges.