Actually they are, you can't separate the two and that includes ownership. I can understand why that would be an unpopular point of view for a lot of people, but that does not make it any less true. Just to make things clear I'm not saying Bitcoin or bitcoins don't have value, nor that you can't put a monetary price on the ability to affect the use of bitcoins in the network, but that does not equal property.

I think you could argue that bitcoin addresses are so hard to find that they are similar to staking a claim, but when there is no registration or authority to register that claim, how can this be considered property? Best analogy I can think of at the moment is that bitcoin-addresses are similar to discovering a unique celestial object (like an asteroid), you can decide to share that discovery with others or keep it secret, but other than naming it (and in the case of bitcoin that means being able to influence it), you do not own it. As far as I can tell, you can't call dibs in Bitcoin.

I'm not a lawyer, I don't know if having the ability to do something, could be considered property and that taking that ability away without compensation is punisheable similar to theft.