What does it mean to own #bitcoin ?
The answer is not as clear as it may first appear! You can have knowledge of a private key that lets you spend some UTXO on the network, but do you 'own' that private key? Someone else could also have knowledge of it, after all. How can you own a number? 'Owning' has an implied exclusivity, but data/numbers are abstract concepts which are not exclusive by nature.
Stack exchange user @redgrittybrick explains this nicely here: https://bitcoin.stackexchange.com/questions/103873/what-exaclty-does-owning-cryptocurrency-mean
'Ownership' is a human concept, enforceable at a social level. After all, users would normally say "I own some BTC", not "I have knowledge of a key that lets me spend some BTC".
If you happened to find a key that can spend someone else's coins, doing so would constitute theft, by human convention.
Practically, 'ownership' is only ensured via an exceedingly large bitcoin keyspace: the chance of someone else generating a privkey that can spend your funds is basically zero.
A few related points:
- A UTXO does not have to be unlocked by a scriptsig that includes a signature from a privkey. eg, the hash-collision bounties that @pete created. Does it make sense to talk about who 'owns' those?
- Faketoshi has recently made legal threats, demanding that devs write code to give him control of coins that he claims were stolen from him. In this case, he claims social-layer ownership, but obviously does not have protocol-level 'ownership'. (obvious fraud aside)
@htimsxela No it doesn't. Those "bounties" could be collected automatically by anyone. They are so trivial to spend even automated software run by miners could direct them to fees.
@pete right, if anything the protocol-layer idea of ‘ownership’ of any of those UTXOs would include knowledge of a hash collision that satisfies the scriptsig, in addition to the ability to (solo) mine a block that includes the spending transaction. Quite convoluted, compared to a naive definition of ‘ownership’!