Ow ah! you guys heard? Nicehash Hacked. 60+ million Gone!
I was also thinking about this.
How they can be hacked. First you have to know on which IP address is wallet? How they know that?
Second, you need a private key for sending coins from locked wallet. How did they get it?
And then main question, how we can protect our self?
Chances that it was inside job are pretty high imo! They claim it was a sophisticated social engineering attack...