https://www.theverge.com/2018/2/15/17017374/coinbase-cryptocurrency-bitcoin-ether-unauthorized-charges

A growing number of Coinbase customers are complaining that the cryptocurrency exchange withdrew unauthorized money out of their accounts. In some cases, this drained their linked bank accounts below zero, resulting in overdraft charges.

In a typical anecdote posted on Reddit, one user said they purchased Bitcoin, Ether, and Litecoin for a total of $300 on February 9th. A few days later, the transactions repeated five times for a total of $1,500, even though the user had not made any more purchases. That was enough to clear out this user’s bank account, they said, resulting in fees.