To steal something implies that there was a legitimate owner of that something. Be it a physical thing or intellectual property.

Now, if someone is stupid enough to think that they own information which is computable in a way that holds no patents or rights, then they very much deserve a lesson in what "property" means from a legal (social-enforced) perspective.

Now, do you understand what "public" means in the compound term of "public key"?

It means that some bits of information is known to everyone, and it is information that does not have any owner or rights attached to it.

Now, back to basics. Let us say you create a "private key" and you declare yourself as its owner. What rights do you have over it? ZERO.

Did someone buy the rights to use the bits 0 and 1 to represent information and we didn't get the memo?

There is no such thing as an owner of a private key. There is only the art of trying to protect a freaking mathematical number to remain undisclosed.

Now - did someone buy the rights to use numbers? Did someone bought an actual number, and has the legal right to be the single entity in the society that has the rights to ever use it? We didn't get the memo on that as well.

No one ever fought a class suit process because somebody else used some number they wrote on some piece of paper.

EVERYONE owns ALL the numbers that can ever exist. You cannot "steal" a number from someone.

But it is true that stupidity costs a lot. We have a saying in my country: the one who's stupid is not the one who ASKS, but the one who GIVES.

So, if you give out your number, and you worked a LOT to get at it, guess what? You never owned it.