However, this is only assumed to be legitimate because there is no way to determine who minght be the legitimate owner of those coins from within the system itself.
I am not disputing the legitimacy of the possession. I am arguing over the meaning of ownership, whatever is legitimate or illegitimate. Moreover, there is a method to determine who is the legitimate owner the electronic coins:
http://bitcoin.org/bitcoin.pdfThus, possession of the private keys must be presumed to have been aquired honestly.
The Bitcoin protocol do not presume "honestly" to determine ownership.
Either way, the coping of the private keys, which are simply numbers, isn't theft of property; it's theft of the access to that property.
The act of steal requires a direct subject. If you steal my door key to grab my computer with the private keys to obtain the ownership of my electronic coins, you have stolen my Bitcoins, not my access to that electronic coins. The result of your criminal act is defined by your initial intention. Whatever method you use to obtain the ownership, you are acting to possess something you were not allowed with no intention to give back to me.
If I give you my door key, my computer password and ask you to verify if is any problem in the Windows registry, and then you copied my wallet.dat file to obtain the private key and posses my electronic coins, you are not stealing my access to that electronic coins. I granted you the access myself! You are indeed copying something you were not allowed with no intention to give back to me.
In this particular case, that property isn't tangible, but nor is it digital;
If is not digital, what is
http://oxforddictionaries.com/definition/english/digital?q=digitalit's simply a concept that, by using this system, we have implicitly agreed to. That the transaction entries in the blockchain represent the (presumed legtimate) transfer of value. This is no different than the tranfer of value that occurs within banking computers daily. It's entirely abstract. IT comes down to agreements. You own what you own because you have a honest claim to it that I do not, and I can coose to honor that claim or not, but society at large develops a consensus upon ownership.
I own because I own because I own...
Circular logic.
I own my electronic coins in the blockchain because I posses the private keys which allows the Bitcoin protocol verify the previous ownership of my electronic coins with the society's consensus (miners).