It has been reported that Hackers have stolen Bitcoin from South Korean Largest Bitcoin and Ethereum Exchange.
Almost 30,000 customers' data has been compromised. To read more :
http://www.bbc.com/news/technology-40506609
http://www.coindesk.com/korean-bitcoin-exchange-to-pay-back-account-thefts/
http://www.businessinsider.com/south-korean-bitcoin-exchange-bithumb-hacked-ethereum-2017-7