By possessing bitcoin,you get the right to hold,sell,spend or let it lay idle in your wallet>Once you lose it anyhow you also lose the right to claim its ownership
I get your point. But I'm not sure we should use the word "right" as a "positive right", as some people (governments) could enforce this right (and be aggressive toward some people).
I have one more example that could actually arise in reality:
> B sends money to A (and A sends "something" or some information to B). Then, we don't know why, everyone decides to change their Bitcoin rules and the result is that A can't get to spend his money in the new version.
So does A have a right to force other participants to use his arbitrary version of the Bitcoin, in order to be able to spend his money? I mean, could his justification of "I have the right to spend those bitcoins" be used while he attacks other people when trying to force them to change their stuff on their computers? I'm thinking about governments behavior and analogous justifications. Since I believe that bitcoins aren't priv. prop., that kind of justification is wrong.