How can he do someting sloppy like that ? Dont he know that blockchain doesnt store our key

The important lesson for me is to keep our keys in the safe place, i usually write it in the notepad and keep it as .rar files and set password for it, for the viruses attack case, i also copy that in other hardware that didnt connect each other.
And last, i write it manually in the paper and store it in my safebox.
Maybe my way to store it too traditionally for this advanced technology, but i believe it is the safes way to keep it.