... the term "Bitcoin fraud" might properly be defined to also include any kind of fraud that involves attempts to take someone's Bitcoins.)
The 'victim' would have to establish that the bitcoins were his. Since both parties have the private key, there is no way to establish that, unless you institute a single central incorruptible authoritative registry of bitcoin keys and their owners.
If I try to say: MP3 fraud is a wide-ranging term for theft and fraud committed using an MP3 file or any similar audio file as a fraudulent source of funds in a transaction. The purpose may be to obtain goods without paying, or to obtain unauthorized funds from an account. ... the statement no longer makes sense.
I'm not so sure. Suppose I create an mp3 and I sell copies in order to buy bread. If you sell it, then that would constitute a fraudulent source of funds for you. Of course, you could just give away copies for free. But then, someone could steal my bitcoins and give them away for free too, in which case the second receiver would be free to do as he pleases.
If the data is copied, the 'owner' still has the original, therefore there is no theft - nothing has been lost. The rest, executing instructions and mathematical functions on a computer, is not a violation of NAP. See this post below from the thread I cited before; it's the second post in that thread and is quite representative of many who contributed there (boldface mine):
Intellectual property is incompatible with Libertarianism.
If you want to own a idea then don't share it with anyone. Telling me what I can and can't do with my pen and my paper is claiming ownership over my pen and paper. That's little more than theft.
If you sell me a book, you are free to set the terms of the purchase. If you want me to sign a contract that says I can't make copies of that book, that's possible. However, if I violate that contract and show it to a third party, that third party is under no contract and can do whatever they want, including, making copies of it.
A computer is physical property. Hacking is trespassing on that physical property.
nybble41 has already answered this above - I cannot instruct your computer to do anything it is not already programmed to do. Refusing me permission to interact freely with my computer would be a violation of the NAP.
Exactly the same as if you walk into my bank with a false beard and pretend to be me and transfer funds into your bank account. You have deprived me of a stored sum of wealth without my permission.
nybble41 replied to this much better than me.
And Casacius is right, most of the libertarians I converse with, even the more strident ones are still in favor of IP laws.
The thread I quoted seems to suggest otherwise. But I accept your statement. This is precisely why I started this thread talking about anti-IPR - I wanted to avoid generalizing to libertarianism and risk getting it wrong.
I think I see what you are trying to get at but I think you need to think about things a little more deeply because you're conflating two different but not dissimilar concepts..
Can you explain a bit more? It would be great if someone holdings NghtRppr's (of the quote above) views would contribute here because I really feel that copying and using an mp3 is very similar to copying and using a bitcoin private key. Or, alternatively, you'd need an arbitrary law like "numbers that make up an mp3 are not protected, but numbers that make up a BPK are protected".