There are two sides of the same coin. I was stupid enough to publish the key, so actually it's been my own fault. Yet, what he did then was 100% criminal. Instead of stealing my money he could have even sent me a message telling me: Hey you did publish something private. That's what I would have done.
But we can't expect everybody in this world to be a good person. Unfortunately, we can't.
Thanks for your compassion @rjunaid12!